Child eating behaviors are consistently linked to intake across meals that vary in portion size

Prior studies evaluating a single meal in children characterized an "obesogenic" style of eating marked by larger bites and faster eating. It is unclear if this style is consistent across portion sizes within children so we examined eating behaviors in 91 children (7-8 years, 45 F) without obesity (BMI<90th percentile). Children consumed 4 ad libitum meals in the laboratory consisting of chicken nuggets, macaroni, grapes, and broccoli that varied in portion size (100%, 133%, 166%, 200%) with a maximum of 30 min allotted per meal. Anthropometrics were assessed using age and sex adjusted body mass index (BMI) percentile and dual energy x-ray absorptiometry. Bites, sips, active eating time, and meal duration were coded from meal videos; bite size (kcal and g/bite), proportion of active eating (active eating time/meal duration), and eating rate (kcal and g/meal duration) were computed. Intraclass correlation coefficients (ICC) showed that most eating behaviors were moderately consistent across portions (>0.50). The consistency of associations between eating behaviors and total meal intake and adiposity were assessed with general linear models adjusted for food liking, pre-meal fullness, age, and sex. Across all portions, more bites, faster eating rate, and longer meal duration were associated with greater intake. While higher BMI percentile was associated with faster eating rates across all meals, greater fat mass index was only associated with faster eating at meals with portions typical for children (i.e., 100% and 133%). In a primarily healthy weight sample, an 'obesogenic' style of eating was a consistent predictor of greater intake across meals that varied in portion size. The consistent relationship of these behaviors with intake makes them promising targets to reduce overconsumption.

Does 'portion size' matter? Brain responses to food and non-food cues presented in varying amounts

Larger portions of food elicit greater intake than smaller portions of food, particularly when foods are high in energy density (kcal/g; ED). The neural mechanisms underlying this effect remain unclear. The present study used fMRI to assess brain activation to food (higher-ED, lower-ED) and non-food (office supplies) images presented in larger and smaller (i.e., age-appropriate) amounts in 61, 7-8-year-olds (29 male, 32 female) without obesity. Larger amounts of food increased activation in bilateral visual and right parahippocampal areas compared to smaller amounts; greater activation to food amount (larger > smaller) in this cluster was associated with smaller increases in food intake as portions increased. Activation to amount (larger > smaller) was stronger for food than office supplies in primary and secondary visual areas, but, for office supplies only, extended into bilateral parahippocampus, inferior parietal cortex, and additional visual areas (e.g., V7). Activation was greater for higher-vs. lower-ED food images in ventromedial prefrontal cortex for both larger and smaller amounts of food; however, this activation extended into left lateral orbital frontal cortex for smaller amounts only. Activation to food cues did not differ by familial risk for obesity. These results highlight potentially distinct neural pathways for encoding food energy content and quantity.

'You just eyeball it': Parent and nursery staff perceptions and influences on child portion size: A reflexive thematic analysis

Background: Childhood obesity is one of the most serious public health epidemics of the 21st century. Observational studies report that increases in portion size (PS) have occurred in parallel with levels of obesity. Increased PSs of high-energy-dense foods can promote overeating, and without compensatory behaviours, can contribute to childhood obesity. Caregivers make decisions about PSs for children in the home and nursery environment, thus are gatekeepers to child food intake. Understanding caregiver PS decisions can aid in the best practice of PS provision to young children. The aim of this study was to explore parent and nursery staff influences on child PS selection and their suggestions for useful tools/strategies in PS decisions. Methods: A qualitative design was employed using focus group discussions (FGDs) with parents and nursery staff of children aged 3-5 years. FGDs were employed given their ability to generate rich data, as well as permit the exploration of collective perceptions, attitudes, behaviours and experiences. Data were analysed using an inductive, semantic approach to reflexive thematic analysis. Results: Four FGDs were conducted: two with parents (n = 13), two with nursery staff (n = 17). Four overarching themes were derived: (i) awareness of PS guidelines; (ii) control over PS; (iii) social influences on children's eating behaviours; (iv) child-specific, social and external factors influencing parent and nursery staff PS decisions. Additionally, participants discussed tools/strategies they believe would be useful in PS decisions. Conclusion: Data from the themes suggest that caregiver control, social, child-specific and external factors are more influential than PS guidelines in both parent and nursery staff PS decisions for young children aged 3-5 years. These findings can inform future childhood obesity prevention initiatives focussed on improving parent and nursery staff provision/use of age-appropriate PSs.

Poorer inhibitory control was related to greater food intake across meals varying in portion size: A randomized crossover trial

Individuals eat more food when larger portions are served, and this portion size effect could be influenced by inhibitory control (the ability to suppress an automatic response). Inhibitory control may also relate to obesogenic meal behaviors such as eating faster, taking larger bites, and frequent switching between meal components (such as bites of food and sips of water). In a randomized crossover design, 44 adults ate lunch four times in the laboratory. Lunch consisted of a pasta dish that was varied in portion size (400, 500, 600, or 700 g) along with 700 g of water. Meals were video-recorded to assess meal duration and bite and sip counts, which were used to determine mean eating rate (g/min), mean bite size (g/bite), and number of switches between bites and sips. Participants completed a food-specific stop-signal task, which was used to calculate Stop-Signal Reaction Time (SSRT). Across participants, SSRT values ranged from 143 to 306 msec, where greater SSRT indicates poorer inhibitory control. As expected, serving larger portions increased meal intake (p < 0.0001); compared to the smallest portion, intake of the largest increased by 121 ± 17 g (mean ± SEM). SSRT did not moderate the portion size effect (p = 0.34), but individuals with poorer inhibitory control ate more across all meals: 24 ± 11 g for each one SD unit increase in SSRT (p = 0.035). SSRT was not related to eating rate or bite size (both p > 0.13), but poorer inhibitory control predicted greater switching between bites and sips, such that 1.5 ± 0.7 more switches were made during meals for each one SD unit increase in SSRT (p = 0.03). These findings indicate that inhibitory control can contribute to overconsumption across meals varying in portion size, potentially in part by promoting switching behavior.

Development of Momentary Appetite Capture (MAC): A versatile tool for monitoring appetite over long periods

Understanding how an intervention impacts appetite in real-life settings and over several days remains a challenging and under-explored research question. To this end, we developed Momentary Appetite Capture (MAC), a form of ecological momentary assessment that combines automated text messaging with an online platform. Participants report their appetite using visual analogue scales (hunger, desire to eat, and fullness) and a virtual portion-size selection task. In two separate studies, we assessed the feasibility and test-retest reliability of MAC. Participants were prompted every 2 hours over a 14-hour window, and they repeated this assessment over two consecutive weekdays. For each participant, we calculated a daily time-averaged area under the curve (AUC) for each appetite measure. In Study One (N = 25) time-averaged AUC was significantly positively correlated across test days for hunger (r = 0.563, p = .003), desire to eat (r = 0.515, p = .008) and prospective portion size (r = 0.914, p < .001), but not for fullness (r = 0.342, p = .094). Participants completed 95% of MACs (380 of 400), and we used participant feedback to improve the MAC tool and study protocol for Study Two. In Study Two (N = 31), 94% of MACs were completed (468 of 496). Across days, time-averaged AUC was significantly positively correlated for hunger (r = 0.595, p = < .001), fullness (r = 0.501, p = .004), desire to eat (r = 0.585, p < .001), and prospective portion size (r = 0.757, p < .001). Together, these studies suggest that MAC could be an acceptable and reliable tool to track appetite throughout the day. In the future, MAC could be used to explore the impact of weight-loss interventions on natural fluctuations in appetite.

Empirically derived portion sizes from the DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study for 4- to 18-year-old children and adolescents to simplify analysis of dietary data using FFQ

OBJECTIVE

To apply FFQ, knowledge about portion sizes is relevant. According to increased energy and nutrient requirements, average portion sizes of foods are supposed to increase during growth. We provide empirically derived portion sizes for 4- to 18-year-olds in different age groups to facilitate analyses of FFQ data in children and adolescents.

DESIGN

Using data from the dynamic DOrtmund Nutritional and Anthropometric Longitudinally Designed cohort study, quantile regression for smoothing percentiles was used to derive portion sizes as a function of age from which age- and food group-specific portion sizes were calculated as median food group intake (g).

SETTING

Dortmund, Germany.

PARTICIPANTS

Data from 3-day weighed dietary records (WDR) of 1,325 participants (♀: 653) were analysed. Participants provided in total 9,828 WDR (on average 7·5 per participant) between 1985 and 2022. WDR were grouped into five age groups, whereby each age group covered 3 years of age.

RESULTS

In total, 11 955 food items were reported and categorised into sixteen major food groups with seventy-one sub-groups. Portion sizes tended to increase with age, except for milk- and plant-based alternatives. Comparing 4- to 6-year-olds to 16- to 18-year-olds, portion size increased between 22·2 % (processed meat: 18 g v. 22 g) and 173·3 % (savoury snacks: 15 g v. 41 g).

CONCLUSION

We provide empirically derived portion sizes for children and adolescents. These data are useful to establish dietary assessment methods based on estimates of portion sizes, such as FFQ, for children and adolescents.

Associations between dietary variety, portion size and body weight: prospective evidence from UK Biobank participants

'Dietary variety' has been identified as a factor associated with food intake. Whilst this relationship may have longer-term benefits for body weight management when eating low-energy, nutrient-dense foods, it may increase the risk of overconsumption (and body adiposity) when foods are high energy density. This study sought to further explore pathways underpinning the relationship between dietary variety and body weight, by considering energy density as a moderating factor and portion size as a mediating factor in this relationship. Using prospective data from the UK Biobank, dietary variety scores (DVS), cumulative portion size and energy density were derived from 24-h dietary recall questionnaires at baseline and follow-up. BMI, whole-body fat percentage and fat-free mass were included as outcomes. Contrary to predictions, linear multiple regression models found some evidence of a negative, direct association between DVS and body weight outcomes at baseline (b = -0·13). Though dietary variety was significantly associated with larger portions across time points (b = 41·86-82·64), a moderated mediation effect was not supported at baseline or follow-up (Index ≤ 0·035). Taken together, these findings provide population-level evidence to support a positive association between variety and food intake, which in turn has potential implications for body weight management, both in terms of moderating food intake and benefitting diet quality.

Variety and portion size combine to increase food intake at single-course and multi-course meals

Increases in food variety and portion size independently promote intake. Little is known about how these effects combine or how they depend on meal structure. In two randomized crossover experiments, once a week for four weeks, women ate a lunch meal that was varied in two properties: variety (low: three bowls of the favorite dish vs. high: three bowls, each with a different main dish) and portion size (small: 450 g vs. large: 600 g). In Experiment 1 (n = 42), dishes were served simultaneously and in Experiment 2 (n = 49), dishes were served sequentially over three courses. At each meal, the primary outcome of food intake was measured; additionally, we measured sensory-specific satiety (SSS; the relative hedonic decline of a food as it is eaten). In Experiment 1 (simultaneous structure) variety and portion size did not interact (p = 0.72) but both independently increased intake; participants consumed 15 ± 7 g more at meals with high variety compared to low and 57 ± 7 g more from large portions compared to small (both p < 0.03). Similarly, in Experiment 2 (sequential structure) variety and portion size did not interact (p = 0.99) but participants consumed 30 ± 8 g more at high-variety meals and 51 ± 8 g more from large portions (both p < 0.001). SSS was not influenced by portion size in either experiment (both p > 0.16) or by variety in Experiment 1 (p = 0.58), but SSS was smaller at high-variety meals in Experiment 2 (p = 0.001). Thus, variety and large portions promoted greater food intake for a similar or smaller hedonic decline, indicating these effects were facilitated by delayed SSS. At meals with either a simultaneous or sequential structure, high variety and large portions combined to increase intake, suggesting that these common properties act together to promote overconsumption.

Portion size affects food selection in an immersive virtual reality buffet and is related to measured intake in laboratory meals varying in portion size

A crucial step for validating the utility of an immersive virtual reality (iVR) buffet to study eating behavior is to determine whether variations in food characteristics such as portion size (PS) are relevant predictors of food selection in an iVR buffet. We tested whether manipulating PS in an iVR buffet affects the weight of food selected, and whether this response to PS is similar to participants' measured intake when PS varies at laboratory meals. In a randomized crossover design, 91 adults (18-71 y; 64 females; BMI = 25.3 ± 5.7) used their iVR remote to select lunch and dinner portions from an iVR buffet before consuming a standardized lab meal at two visits separated by one week. The PS in the iVR buffet and lab meals varied between a standard PS and a large PS. This design enabled comparisons of PS effects between iVR and lab settings, despite the scale difference in food weight between the environments. Portion size significantly affected food selection and food intake (p < 0.001). Subjects selected an additional 350 g in iVR and consumed an additional 154 g of food in the lab meals when offered the large portion compared to the small portion. The effect of PS showed a similar percentage increase in iVR (36.5%) and lab meals (39.2%). There was no significant difference in the effect of PS between iVR and lab meals after accounting for scale differences in food weight between the environments. The response to PS was not influenced by subject characteristics such as body mass index, sex, or age. These results demonstrate the utility of iVR for replicating real-world eating behaviors and enhancing our understanding of the intricate dynamics of food-related behaviors in a variety of contexts.

A qualitative exploration of food portion size practices and awareness of food portion size guidance in first-time parents of one- to two-year-olds living in the UK

BACKGROUND

Food portion size guidance resources aimed at parents of young children in the UK are freely available from a number of credible sources. However, little is known about whether parents are aware of, and use, any of these resources to guide their food portioning practices.

OBJECTIVES

We aimed to explore the food portion size practices used by first-time parents living in the UK when feeding their one- to two-year-old child, and their awareness of and views on six food portion size guidance resources.

METHODS

Participants were recruited via parent Facebook groups and online parent forums. Online 1-1 semi-structured interviews were conducted, during which parents were shown images of six food portion size guidance resources to facilitate discussion. Data was analysed in NVivo 11 using a Reflexive Thematic Analysis approach.

RESULTS

Of the 27 participants, most were women (n = 25), white (n = 18), and educated to first degree level or higher (n = 24). First-time parents mostly relied on their own judgement and "instinct" to portion foods, based on their learned experience of how much their child ate on a day-to-day basis. This experience was used alongside physical indicators of food portion size, such as the size of children's dishware and food packaging. Most participants were unaware of any of the six food portion size guidance resources we showed them; only four had read any of the resources. Parents suggested they had previously sought advice about weaning from a range of sources (e.g. online, friends, community groups) but would be unlikely to seek out specific food portion size guidance. Parents suggested recommendations on food portion size should acknowledge and highlight parents' perception that "every child is different".

CONCLUSIONS

Existing food portion size guidance resources for parents of young children in the UK are ineffective as they have poor reach and impact. We suggest parents should be involved in developing novel strategies to promote age-appropriate consumption and healthy weight gain in young children.

Children with lower ratings of executive functions have a greater response to the portion size effect

Deficits in executive functions (EFs), a set of cognitive processes related to self-regulation, are associated with the development of obesity. Prior studies from our group showed that lower food-cue related activation in brain regions implicated in self-regulation was related to a larger portion size effect. We tested the hypothesis that lower EFs in children would be positively related to the portion size effect. Healthy weight children aged 7-8 y (n = 88), who varied by maternal obesity status, participated in a prospective study. At baseline, the parent primarily in charge of feeding completed the Behavior Rating Inventory of Executive Function (BRIEF2) to assess child EFs, including Behavioral (BRI), Emotional (ERI), and Cognitive (CRI) indices. At 4 baseline sessions, children consumed meals in which the portion sizes of foods (pasta, chicken nuggets, broccoli, and grapes) varied by visit (total meal weight of 769, 1011, 1256, or 1492g). Intake increased with increasing portions in a linear trajectory (p < 0.001). EFs moderated the portion size effect such that lower BRI (p = 0.003) and ERI (p = 0.006) were associated with steeper increases in intake as portions increased. As amount of food increased, children in the lowest functioning tertiles for BRI and ERI increased intake by 35% and 36%, respectively, compared to children in the higher tertiles. Increases in intake among children with lower EFs were for higher- but not lower-energy-dense foods. Thus, in healthy weight children who varied by obesity risk, lower parentally reported EFs were associated with a larger portion size effect, and these results were independent of child and parent weight status. Therefore, EFs may be target behaviors that could be strengthened to help children moderate excess intake in response to large portions of energy-dense foods.

Impact on sales of adding a smaller serving size of beer and cider in licensed premises: an A-B-A reversal design

BACKGROUND

Smaller serving sizes of alcoholic drinks could reduce alcohol consumption across populations thereby lowering the risk of many diseases. The effect of modifying the available range of serving sizes of beer and cider in a real-world setting has yet to be studied. The current study assessed the impact on beer and cider sales of adding a serving size of draught beer and cider (2/3 pint) that was between the current smallest (1/2 pint) and largest (1 pint) standard serving sizes.

METHODS

Twenty-two licensed premises in England consented to taking part in the study. The study used an ABA reversal design, set over three 4-weekly periods, with A representing the non-intervention periods, during which standard serving sizes were served and B the intervention period when a 2/3 pint serving size of draught beer and cider was added to the existing range, along with smaller 1/2 pint and larger 1 pint serving sizes. The primary outcome was the daily volume of beer and cider sold, extracted from sales data.

RESULTS

Fourteen premises started the study, of which thirteen completed it. Twelve of those did so per protocol and were included in the primary analysis. After adjusting for pre-specified covariates, the intervention did not have a significant effect on the volume of beer and cider sold per day (3.14 ml; 95%CIs -2.29 to 8.58; p = 0.257).

CONCLUSIONS

In licensed premises, there was no evidence that adding a smaller serving size for draught beer and cider (2/3 pint) when the smallest (1/2 pint) and largest (1 pint) sizes were still available, affected the volume of beer and cider sold. Studies are warranted to assess the impact of removing the largest serving size.

TRIAL REGISTRATION

ISRCTN: https://doi.org/10.1186/ISRCTN33169631 (08/09/2021), OSF: https://osf.io/xkgdb/ (08/09/2021).

Impact of the economic crisis on food consumption of Sri Lankans: An online cross-sectional survey

AIMS

This study investigated how the economic crisis has changed Sri Lankans' food consumption.

METHODS

A web-based cross-sectional survey was carried out in the month of July 2022, using an e-questionnaire based on Google Forms. The questionnaire assessed respondents' socio-demographics, food consumption, and dietary patterns before and during the economic crisis. The changes were compared using descriptive statistics and inferential statistics.

RESULTS

A total of 1095 respondents, aged ≥18 years were included in the survey. There was a significant reduction in the average consumption of main meals per day during the economic crisis (pre: 3.09 ± 0.42, post: 2.82 ± 0.47; P < 0.001). The intake of food items such as rice, bread, and snacks also reduced significantly (P < 0.001). The average daily milk intake frequency decreased from 1.41 ± 1.07 to 0.57 ± 0.80 meals/day (P < 0.001). On contrary, the intake of non-dairy beverages such as malted milk and "plain tea" has increased by several folds. Consumption of fruit and vegetables showed a significant reduction in both frequency and portion size. The consumption of meat, fish, eggs and dhal also decreased in around three-quarters of the study sample. During this period majority (81%) used food coping mechanisms and the most adopted strategy was buying less expensive food.

CONCLUSION

Sri Lankans' food consumption have been adversely altered due to the country's economic crisis. There has been an overall reduction in the amount and frequency of intake of many common food items.

Socioeconomic position and the influence of food portion size on daily energy intake in adult females: two randomized controlled trials

BACKGROUND

Reducing portion sizes of commercially available foods could be an effective public health strategy to reduce population energy intake, but recent research suggests that the effect portion size has on energy intake may differ based on socioeconomic position (SEP).

OBJECTIVE

We tested whether the effect of reducing food portion sizes on daily energy intake differed based on SEP.

METHODS

Participants were served either smaller or larger portions of food at lunch and evening meals (N = 50; Study 1) and breakfast, lunch and evening meals (N = 46; Study 2) in the laboratory on two separate days, in repeated-measures designs. The primary outcome was total daily energy intake (kcal). Participant recruitment was stratified by primary indicators of SEP; highest educational qualification (Study 1) and subjective social status (Study 2), and randomisation to the order portion sizes were served was stratified by SEP. Secondary indicators of SEP in both studies included household income, self-reported childhood financial hardship and a measure accounting for total years in education.

RESULTS

In both studies, smaller (vs larger) meal portions led to a reduction in daily energy intake (ps < .02). Smaller portions resulted in a reduction of 235 kcal per day (95% CI: 134, 336) in Study 1 and 143 kcal per day (95% CI: 24, 263) in Study 2. There was no evidence in either study that effects of portion size on energy intake differed by SEP. Results were consistent when examining effects on portion-manipulated meal (as opposed to daily) energy intake.

CONCLUSIONS

Reducing meal portion sizes could be an effective way to reduce overall daily energy intake and contrary to other suggestions it may be a socioeconomically equitable approach to improving diet.

TRIAL REGISTRATION

These trials were registered at www.

CLINICALTRIALS

gov as NCT05173376 and NCT05399836.

Portion-control tableware differentially impacts eating behaviour in women with and without overweight

Portion control tableware has been described as a potentially effective approach for weight management, however the mechanisms by which these tools work remain unknown. We explored the processes by which a portion control (calibrated) plate with visual stimuli for starch, protein and vegetable amounts modulates food intake, satiety and meal eating behaviour. Sixty-five women (34 with overweight/obesity) participated in a counterbalanced cross-over trial in the laboratory, where they self-served and ate a hot meal including rice, meatballs and vegetables, once with a calibrated plate and once with a conventional (control) plate. A sub-sample of 31 women provided blood samples to measure the cephalic phase response to the meal. Effects of plate type were tested through linear mixed-effect models. Meal portion sizes (mean ± SD) were smaller for the calibrated compared with the control plate (served: 296 ± 69 vs 317 ± 78 g; consumed: 287 ± 71 vs 309 ± 79 g respectively), especially consumed rice (69 ± 24 vs 88 ± 30 g) (p < 0.05 for all comparisons). The calibrated plate significantly reduced bite size (3.4 ± 1.0 vs 3.7 ± 1.0 g; p < 0.01) in all women and eating rate (32.9 ± 9.5 vs 33.7 ± 9.2 g/min; p < 0.05), in lean women. Despite this, some women compensated for the reduced intake over the 8 h following the meal. Pancreatic polypeptide and ghrelin levels increased post-prandially with the calibrated plate but changes were not robust. Plate type had no influence on insulin, glucose levels, or memory for portion size. Meal size was reduced by a portion-control plate with visual stimuli for appropriate amounts of starch, protein and vegetables, potentially because of the reduced self-served portion size and the resulting reduced bite size. Sustained effects may require the continued use of the plate for long-term impact.

Downsizing food: a systematic review and meta-analysis examining the effect of reducing served food portion sizes on daily energy intake and body weight

Portion sizes of many foods have increased over time. However, the size of effect that reducing food portion sizes has on daily energy intake and body weight is less clear. We used a systematic review methodology to identify eligible articles that used an experimental design to manipulate portion size served to human participants and measured energy intake for a minimum of 1 d. Searches were conducted in September 2020 and again in October 2021. Fourteen eligible studies contributing eighty-five effects were included in the primary meta-analysis. There was a moderate-to-large reduction in daily energy intake when comparing smaller v. larger portions (Standardised Mean Difference (SMD) = -0·709 (95 % CI: -0·956, -0·461), approximately 235 kcal (983·24 kJ)). Larger reductions to portion size resulted in larger decreases in daily energy intake. There was evidence of a curvilinear relationship between portion size and daily energy intake; reductions to daily energy intake were markedly smaller when reducing portion size from very large portions. In a subset of studies that measured body weight (four studies contributing five comparisons), being served smaller v. larger portions was associated with less weight gain (0·58 kg). Reducing food portion sizes may be an effective population-level strategy to prevent weight gain.

Switching between bites of food and sips of water is related to food intake across meals varying in portion size

Individuals eat more when served more food, but little is known about how this portion size effect is moderated by meal-related characteristics, particularly the inclusion of water served as a beverage. Patterns of eating and drinking as well as consumption of water could affect satiation by modifying exposure to the sensory qualities of food. In a crossover design, 44 adults ate lunch in the laboratory once a week for 4 weeks and intake was measured. The meal was a pasta dish that was varied in portion size (400, 500, 600, or 700 g) plus 700 g of water. Meals were video-recorded to count bites and sips and the number of switches between them. Sensory-specific satiety (SSS) was evaluated as the relative decline in hedonic ratings of the pasta after consumption. Serving larger portions led to a curvilinear increase in food intake (p < 0.0001). Neither switching between bites and sips nor water intake moderated the portion size effect. Independent of portion served, across all meals switching more frequently was related to greater food consumption (5.7 ± 1.8 g more food consumed for each additional switch, p = 0.004). Greater water intake was also related to greater food intake across portions (1.1 ± 0.5 g more food consumed for each additional 10 g of water, p = 0.025), but this effect was not significant after accounting for switching (p = 0.38). The magnitude of SSS was unaffected by switching, suggesting that switching allowed greater food intake for a given hedonic decline. At a meal with a single food, intake was greater when larger portions were served and also when there was more switching between bites and sips. Switching between food and water may promote energy intake by attenuating the development of SSS.

Eating rate and bite size were related to food intake across meals varying in portion size: A randomized crossover trial in adults

Serving larger portions leads to increased food intake, but behavioral factors that influence the magnitude of this portion size effect have not been well characterized. We investigated whether measures of eating microstructure such as eating rate and bite size moderated the portion size effect. We also explored how sensory-specific satiety (SSS; the relative hedonic decline of a food as it is eaten) was affected by eating microstructure and larger portions. In a randomized crossover design, 44 adults aged 18-68 y (66% women; 46% with overweight and obesity) ate lunch in the laboratory once a week for 4 weeks. The meal consisted of pasta that was varied in portion size (400, 500, 600, or 700 g) and 700 g of water. Meals were video-recorded to assess bite count and meal duration, which were used to calculate mean eating rate (g/min) and mean bite size (g/bite). At each meal participants also completed an assessment of SSS. The results showed that as larger portions were served, meal intake increased in a curvilinear manner (p < 0.0001). Measures of eating microstructure did not moderate the portion size effect but were related to intake across all portions; faster eating rate, larger bite size, higher bite count, and longer meal duration were associated with greater consumption at all meals (all p < 0.0001). SSS was not influenced by any measure of eating microstructure or by portion size (all p > 0.10). In summary, the portion size effect was not moderated by eating microstructure, but relatively faster eating rates and larger bite sizes at meals, along with large portions, combined to increase food intake.

Estimation of meal portions in bulimia nervosa compared to anorexia nervosa and healthy controls

PURPOSE

Bulimia nervosa (BN) and anorexia nervosa (AN) are potentially life-threatening eating disorders (ED) that primarily affect young people, mostly women. The central common pathology is linked to the relationship with food and with abnormalities in food intake. A previous study indicated that individuals with AN tend to overestimate food portion sizes compared to healthy controls (HC), but no study has investigated these patterns in BN, which was the objective of this study.

METHODS

Women with BN (27), AN (28), and HC (27) were asked to rate different meal portion sizes in two conditions: as if they were supposed to eat them (intent-to-eat condition) or in general (general condition). BN results were compared to HC and AN using mixed model analyses.

RESULTS

BN showed larger estimations compared to HC, while smaller estimations compared to AN. These differences were found mostly for intermediate portion sizes. No difference for conditions (intent-to-eat; general) was found between groups.

CONCLUSION

When estimating food portion sizes, individuals with BN seem to fall intermediately between HC and AN. ED symptoms in BN were most strongly associated with higher portion estimation. This might therefore reflect one aspect of the cognitive distortions typically seen also in AN. A therapeutic option could include the frequent visual exposure to increasing portions of food, what may serve to recalibrate visual perceptions of what a "normal-sized" portion of food looks like.

LEVEL OF EVIDENCE

Level II: Evidence obtained from well-designed controlled trials without randomization.

Where and when are portion sizes larger in young children? An analysis of eating occasion size among 1·5-5-year-olds in the UK National Diet and Nutrition Survey (2008-2017)

OBJECTIVE

To identify eating occasion-level and individual-level factors associated with the consumption of larger portions in young children and estimate their relative importance.

DESIGN

Cross-sectional.

SETTING

Data from parent-reported 4-d food diaries in the UK National Diet and Nutrition Survey (2008-2017) were analysed. Multilevel models explored variation in eating occasion size (kJ) within (n 48 419 occasions) and between children (n 1962) for all eating occasions. Eating contexts: location, eating companion, watching TV, and sitting at a table and individual characteristics: age, gender, ethnicity and parental socio-economic status were explored as potential correlates of eating occasion size.

PARTICIPANTS

Children aged 1·5-5 years.

RESULTS

Median eating occasion size was 657 kJ (IQR 356, 1117). Eating occasion size variation was primarily attributed (90 %) to differences between eating occasions. Most (73 %) eating occasions were consumed at home. In adjusted models, eating occasions in eateries were 377 kJ larger than at home. Eating occasions sitting at a table, v. not, were 197 kJ larger. Eating in childcare, with additional family members and friends, and whilst watching TV were other eating contexts associated with slightly larger eating occasion sizes.

CONCLUSIONS

Eating contexts that vary from one eating occasion to another are more important than demographic characteristics that vary between children in explaining variation in consumed portion sizes in young children. Strategies to promote consumption of age-appropriate portion sizes in young children should be developed, especially in the home environment, in eating contexts such as sitting at the table, eating with others and watching TV.

"This snack is too small - I'll take a different one": Quantifying 'norm' and 'choice' boundaries to inform effective portion-reduction strategies

Previous research suggests that portion sizes can be categorised as 'normal' or 'abnormal' and that reduced portions which are still categorised as normal do not promote compensatory responses in intake. However, a critical question remains - will consumers choose a reduced portion product from among standard portion competitors? For the first time, we explore the effects of portion reduction on food choice. Participants (N = 45) categorised 20 different portions (range 40-420 kcal) of five snacks as normal or abnormal (to quantify individual 'norm boundaries' for each food) and rated their desire to eat each snack. Using a 2-alternative forced choice hypothetical task, we then calculated a 'choice boundary' by offering smaller portions of their most-desired snack (range 40-240 kcal) alongside standardised portions (240 kcal) of the less-desired foods. Boundaries were derived using probit analysis (choice boundary mean = 185.8 kcal, SD = 54, norm boundary mean = 127.3 kcal, SD = 49.5) and these deviated significantly (p < .01, d = 0.98, mean difference = 58.0 kcal, SD = 59.1). Critically, this shows that only a small reduction - where the product is still considered normal - can nudge a consumer to select an alternative. Choice boundaries were also affected by differences in desire to eat; when two foods were desired to a similar degree, only minor reductions in the size of the favourite food elicited a switch in choice. Together, these findings indicate that portion reduction can also influence food choice, highlighting the importance of measuring choice boundaries before reformulating commercial products.

Multi-component food-items and eating behaviour: What do we know and what do we need to know?

Multi-component food-items are single food products that comprise more than one food class, brought together usually via some form of processing. Importantly, individual components of the food-item remain discernible and sensorially distinguishable from each other (e.g., chocolate chip cookies or 'choc ice'). Despite a sizable research literature on the formulation of such products, there lacks a concomitant research literature on the effect(s) of multi-component food-items (compared to single component food-items) on eating behaviour. Considerable previous research has investigated the effect of multiple separate food items on food intake, portion size selection and palatability. However, studies rarely use test foods that capture the physical or chemical interactions between components that are characteristic of multi-component foods. Nevertheless, previous research and relevant theory allow us to generate hypotheses about how multi-component foods may affect eating behaviour; consideration of food variety and perceived sensory complexity suggest that consumption of multi-component foods are likely to increase perceived palatability of such foods, self-selected portion size and food intake. Moreover, many (but not all) multi-component foods would be considered ultra-processed, which is a driver of food intake in and of itself. One possibility is that food components brought together as part of a multi-component food-item interact to strongly drive eating behaviour. To explore this idea, researchers will need to work across disciplines to address various practical and methodological barriers including the technical preparation of test foods.

Testing an online measure of portion size selection: a pilot study concerned with the measurement of ideal portion size

BACKGROUND

Portion size is known to be a key driver of food intake. As consumed portions are often pre-planned, 'ideal portion size'-an individual's preferred meal size selected prior to eating-has been identified as a strong predictor of actual consumption. However, assessments of ideal portion size have predominantly relied on laboratory-based computer tasks, limiting use online. Therefore, this cross-sectional study sought to pilot test the validity of a web-based tool to measure ideal portion size.

METHODS

In an online study (N = 48), participants responded to images of a range of foods. Each food was photographed in a series of different portions and loaded into an 'image carousel' that would allow participants to change the size of the displayed portion by moving a slider left-to-right. Using this image carousel, participants selected their ideal portion size. They also completed measures of expected satiety and expected satiation and self-reported their age and body mass index (BMI). A non-parametric correlation matrix was used to explore associations between ideal portion size and identified predictors of food intake.

RESULTS

Supporting convergent validity of this measure, ideal portion size was significantly correlated with expected satiety (rs = .480) and expected satiation (rs = -.310) after controlling for effects of baseline hunger and fullness, consistent with past research. Similarly, supporting divergent validity of this measure, ideal portion size was not significantly correlated with age (rs = -.032) or BMI (rs = -.111,).

CONCLUSIONS

Pilot results support the validity of this web-based portion size selection tool used to measure ideal portion size, though further research is needed to validate use with comparisons to actual food intake.

Predictors of vegetable consumption in children and adolescents: analyses of the UK National Diet and Nutrition Survey (2008-2017)

Children's vegetable consumption is generally below national recommendations in the UK. This study examined predictors of vegetable intake by children aged 1·5-18 years using counts and portion sizes derived from 4-d UK National Diet and Nutrition Survey food diaries. Data from 6548 children were examined using linear and logit multilevel models. Specifically, we examined whether demographic variables predicted vegetable consumption, whether environmental context influenced portion sizes of vegetables consumed and which food groups predicted the presence (or absence) of vegetables at an eating occasion (EO). Larger average daily intake of vegetables (g) was predicted by age, ethnicity, equivalised income, variety of vegetables eaten and average energy intake per d (R2 0·549). At a single EO, vegetables were consumed in larger portion sizes at home, with family members and at evening mealtimes (Conditional R2 0·308). Within EO, certain configurations of food groups such as carbohydrates and protein predicted higher odds of vegetables being present (OR 12·85, 95 % CI 9·42, 17·54), whereas foods high in fats, sugars and salt predicted a lower likelihood of vegetable presence (OR 0·03, 95 % CI 0·02, 0·04). Vegetables were rarely eaten alone without other food groups. These findings demonstrate that only one portion of vegetables was eaten per d (median) and this was consumed at a single EO, therefore falling below recommendations. Future research should investigate ways to encourage vegetable intake at times when vegetables are not regularly eaten, such as for breakfast and as snacks, whilst considering which other, potentially competing, foods are presented alongside vegetables.

Socioeconomic position, energy labelling and portion size selection: An online study comparing calorie and physical activity calorie equivalent (PACE) labelling in UK adults

Limited research has examined the impact of energy labelling on portion size selection. It is also unclear whether physical activity calorie equivalent (PACE) is more effective than standard kilocalorie (kcal) energy labelling in promoting healthier dietary behaviour and whether effectiveness varies based on socioeconomic position (SEP). In the present online study, 1667 UK adults of lower and higher SEP made virtual portion size selections for 18 common main meal foods under one of four conditions: kcal labelling only, PACE labelling only, kcal and PACE labelling, no labelling. Contrary to predictions, participants in the kcal labelling condition (+55 kcal, p < 0.001) chose larger portion sizes compared to the no labelling condition, whereas the PACE labelling (−17 kcal, p = 0.065) and no labelling condition did not significantly differ. The presence of PACE information on labels was associated with selection of significantly smaller portions when compared to labels that only included kcal information. Effects of labels on portion size selection were not moderated by participant SEP in primary analyses. The present study of virtual portion size selections suggests that kcal labelling resulted in larger portion size selections than no labelling, but this counter-intuitive effect was attenuated when kcal and PACE labelling were combined. Further research examining the impact of PACE labelling on real-world food selection in participants of lower and higher SEP is now warranted.

Promoting vegetable intake in preschool children: Independent and combined effects of portion size and flavor enhancement

This study investigated the independent and combined effects on preschool children's vegetable intake of serving a larger portion of vegetables and enhancing their flavor. In a crossover design, lunch was served in childcare centers once a week for four weeks to 67 children aged 3-5 y (26 boys, 41 girls). The meal consisted of two familiar vegetables (broccoli and corn) served with fish sticks, rice, ketchup, applesauce, and milk. Across the four meals, we varied the portion of vegetables (60 or 120 g total weight, served as equal weights of broccoli and corn) and served them either plain or enhanced (6.6% light butter and 0.5% salt by weight). All meals were consumed ad libitum and were weighed to determine intake. Doubling the portion of vegetables led to greater consumption of both broccoli and corn (both p < 0.0001) and increased meal vegetable intake by 68% (mean ± SEM 21 ± 3 g). Enhancing vegetables with butter and salt, however, did not influence their intake (p = 0.13), nor did flavor enhancement modify the effect of portion size on intake (p = 0.10). Intake of other meal components did not change when the vegetable portion was doubled (p = 0.57); thus, for the entire meal, the increase in vegetable consumption led to a 5% increase in energy intake (13 ± 5 kcal; p = 0.02). Ratings indicated that children had similar liking for the plain and enhanced versions of each vegetable (both p > 0.31). All versions of vegetables were well-liked, as indicated by ≥ 76% of the children rating them as "yummy" or "just okay". Serving a larger portion of vegetables at a meal was an effective strategy to promote vegetable intake in children, but when well-liked vegetables were served, adding butter and salt was not necessary to increase consumption.

When do children learn how to select a portion size?

The reduction of portion sizes supports weight-loss. This study looks at whether children have a conceptual understanding of portion size, by studying their ability to manually serve a portion size that corresponds to what they eat. In a clinical setting, discussion around portion size is subjective thus a computerised portion size tool is also trialled, with the portion sizes chosen on the screen being compared to amounts served manually. Children (n = 76) age 5-6, 7-8 and 10-11 were asked to rate their hunger (VAS scale), liking (VAS scale) and 'ideal portion size for lunch' of eight interactive meal images using a computerised portion size tool. Children then manually self-served and consumed a portion of pasta. Plates were weighed to allow for the calculation of calories served and eaten. A positive correlation was found between manually served food portions and the amount eaten (r = 0.53, 95%CI [0.34, 0.82, P < .001), indicating that many children were able to anticipate their likely food intake prior to meal onset. A regression model demonstrates that age contributes to 9.4% of the variance in portion size accuracy (t(68) = -2.3, p = .02). There was no relationship between portion size and either hunger or liking. The portion sizes chosen on the computer at lunchtime correlated to the amount manually served overall (r = .34, 95%CI [0.07, 0.55], p < .01), but not in 5-6-year-old children. Manual portion-size selection can be observed in five-year olds and from age seven, children's 'virtual' responses correlate with their manual portion selections. The application of the computerised portion-size tool requires further development but offers considerable potential.

Individual differences and moderating participant characteristics in the effect of reducing portion size on meal energy intake: Pooled analysis of three randomized controlled trials

Portion size impacts on the amount of energy consumed during a meal. However, research findings on participant characteristics that moderate the effect of portion size on energy intake are mixed. Using data pooled across three randomized control trials, we examined the impact of reducing meal portion size on meal energy intake in 111 adult participants varying in sex (55 M, 56 F), body weight (BMI range = 19-42) and a broad range of participant characteristics, including usual portion size, restrained, emotional and external eating, satiety responsiveness, plate clearing tendencies, concerns about wasting food and self-control. In each trial, a repeated-measures design was used and participants consumed three ad-libitum lunchtime meals differing in portion size; large-normal portion size condition (100%) vs. small-normal portion size condition (~ 75%) vs. smaller than normal portion size condition (~ 50%). In mixed ANOVAs, we did not find convincing evidence that any participant characteristic reliably moderated the impact that reducing portion size had on energy intake. For the majority of participants energy intake decreased when portion size was reduced and it was more common for participants to consistently reduce their energy intake than consume a similar amount when portion size was reduced. We also found little evidence that a sub-group of participants existed whose energy intake was consistently resistant to portion size reductions. Portion size may be a universal driver of energy intake, as reducing meal portion size appears to decrease meal energy intake among most people. Food portion downsizing may therefore be an equitable intervention approach to reducing population level energy intake.

Effect of breakfast cereal type on portion size and nutritional implications

OBJECTIVE

The present study aimed to assess the effect of different types of breakfast cereal (BC) on portion size and the nutritional implications of potential under or overserving.

DESIGN

A cross-sectional analysis was performed using one BC from the seven established BC manufacturing methods (flaking (F), gun puffed (GP), oven puffed (OP), extruded gun puffed (EGP), shredded wholegrain (SW), biscuit formed (BF) and granola). Participants were asked to pour cereal as if they were serving themselves (freepour). Difference between the freepour and recommended serving size (RSS) was calculated (DFR). The Friedman test followed by Dunn's multiple comparison test was used to test for a significant differences between cereal categories.

SETTING

City of Chester, North West of the UK.

PARTICIPANTS

Adults (n 169; n 110 female, 32 (sd 18) years).

RESULTS

Freepour values were greater than RSS for all categories of BC. Median values for denser cereals such as SW, granola and oats were significantly (P < 0·001) greater than all other categories with granola having the highest median freepour value of 95 g. Median (and range of) DFR weight values for granola were significantly higher than other BC (50·0 g (-24·0 to 267·0 g), P < 0·001). BC with the lowest median DFR were F1 (7·0 g (-20 to 63·0 g)), GP (6·0 g (-26·0 to 69·0 g)), EGP (6·0 g (-26·0 to 56·0 g)), OP (5·0 g (-27·0 to 53·0 g)) and BF (0·0 g (-28·2 to 56·4 g)).

CONCLUSIONS

The degree of overserving may be related to the type of BC with denser cereals more readily overserved. Encouraging manufacturers to reformulate cereals and improving their nutritional properties may have benefit in reducing excess energy intake.

real-world settings

External influences on eating behaviour, such as portion size, have been reliably shown to influence food intake in the laboratory. However, little research has examined whether laboratory settings under or overestimate the effect that external influences have on food intake compared to when studied in the real-world. In Study 1, 60 participants (mean age = 32 years) were randomized to consume a large (200 g) or small (100 g) portion of popcorn under controlled laboratory conditions and during a separate session in their home. Results showed that the effect of portion size on food intake was larger at home (d = 0.97) than in the laboratory (d = 0.56). Furthermore, participants reported feeling more relaxed eating at home compared to the laboratory. In Study 2, we examined whether comparable results were observed in a semi-naturalistic laboratory designed to resemble a home setting. 59 participants (mean age = 28 years) completed the same procedure as Study 1 in a standard and a semi-naturalistic laboratory setting. Although participants reported having higher levels of private self-awareness in the standard laboratory, the effect that portion size had on food intake did not differ between the standard laboratory (d = 0.50) and the semi-naturalistic laboratory (d = 0.49). The impact that external influences on eating, such as portion size, have on food intake in the real-world may be underestimated when studied under laboratory conditions.

Evaluation of portion size estimation aids for the Korea National Health and Nutrition Examination Survey

BACKGROUND/OBJECTIVES

This study aimed to improve portion size estimation aids (PSEAs) used in the nutrition survey of the Korea National Health and Nutrition Examination Survey (KNHANES) and validate the accuracy and precision of the newly developed aids.

SUBJECTS/METHODS

We conducted intensive interviews with survey experts in KNHANES and consulted with experts to collect opinions about improvement of PSEAs. Based on the results of the interviews, 5 types of PSEAs (rice bowl, earthen pots, mounds, measuring spoons, and thickness sticks) were newly developed using 3-dimensional (3D) modeling or modification of color or shape. Validation tests were conducted with 96 adults 20 years old or older. For the rice bowl and earthen pots, the participants were asked to select the more similar PSEA in size after being shown the real dishes. For the mounds, measuring spoons, and thickness sticks, the participants were presented with actual plates of food and asked to estimate the given portion sizes using the given PSEAs.

RESULTS

The improved 2-dimensional (2D) picture aid for the rice bowl reflecting the size distortion by angle of view using 3D modeling was perceived more closely to the actual size than the current 2D picture (P < 0.001). The change of the color of 2D pictures and 3D models, the change of shape of the measuring spoons, and the 3-dimensionalization of the 2D mounds had no significant improvement in the subjects' perception.

CONCLUSIONS

The currently used 2D PSEAs need to be fully redesigned using 3D modeling to improve subjects' perception. However, change of color or shape will not be necessary. For amorphous foods, it is suggested that more evaluation be performed before reaching a final conclusion in the use of PSEAs, or alternative ways to improve accuracy of estimation need to be explored.

Assessing intake and consumption level of spices among urban and rural households of Ludhiana district of Punjab, India

Background

Spices are the esoteric food adjuncts that are used for enhancing the sensory quality of the food in Punjabi diets and add many health benefits. Estimating the intake of spices at the individual level is a challenging task as they are consumed in very small quantities as compared to other foods. The present study aimed to assess the intake and spices consumption level of spices among urban and rural households.

Methods

A study was carried out among 100 households each from urban and rural areas from Ludhiana district of Punjab, India to collect the information regarding frequency of spice usage and portion sizes using a questionnaire. The information pertaining to sociodemographic characteristics of female respondents from urban and rural households were also collected. The commonly used 25 spices in Punjabi diets were selected to assess their dietary intake at the individual level among households.

Results

Spice consumption frequency was more in urban households in comparison to rural households. The maximum mean consumption frequency score among urban and rural households was observed for red chilli powder (5.00) and turmeric powder (5.00). Maximum percentage (76 and 72%) of urban and rural households preferred to use the unroasted form of spices, respectively. The highest mean intake and range was observed for red chilli powder (3.19 g with range 0.35–5.23 g) among urban women and (2.41 g with range 0.25–3.75 g) for rural women. Spice intake from individual dishes showed the maximum number of portion sizes for red chilli powder that were from vegetable>dhal > curry preparations among urban and dhal > vegetable>curry preparation among rural households. Average amount of spices consumed by urban adult women was 10.04 g per day which was higher as compared to spices consumed by rural adult women per day (7.68 g).

Conclusions

The study concluded that the urban households showed higher consumption of spices as compared to rural households thus assessing the quantifying intake of spices. Urban adult women consumed more spices per day as compared to rural women. Therefore, more encouragement for increased use of spices is required to reap various health benefits of spices in combating metabolic disorders.

Reliability and responsiveness of virtual portion size creation tasks: Influences of context, foods, and a bariatric surgical procedure

Food portion size influences energy intake and sustained high-energy intake often leads to obesity. Virtual portion creation tasks (VPCTs), in which a participant creates portions of food on a computer screen, predict intake in healthy individuals. The objective of this study was to determine whether portions created in VPCTs are stable over time (test-retest reliability) and responsive to factors known to influence food intake, such as eating contexts and food types, and to determine if virtual portions can predict weight loss. Patients with obesity scheduled for bariatric surgery (n = 29), and individuals with a normal BMI (18.5-24.9 kg/m2, controls, n = 29), were instructed to create virtual portions of eight snack foods, which varied in energy density (low and high) and taste (sweet and salty). Portions were created in response to the following eating situations, or "contexts": What they would a) eat to stay healthy (healthy), b) typically eat (typical), c) eat to feel comfortably satisfied (satisfied), d) consider the most that they could tolerate eating (maximum), and e) eat if nothing was limiting them (desired). Tasks were completed before, and 3 months after, surgery in patients, and at two visits, 3 months apart, in controls. Body weight (kg) was recorded at both visits. Virtual portions differed significantly across groups, visits, eating contexts, energy densities (low vs. high), and tastes (sweet vs. salty). Portions created by controls did not change over time, while portions created by patients decreased significantly after surgery, for all contexts except healthy. For patients, desired and healthy portions predicted 3-month weight loss. VPCTs are replicable, responsive to foods and eating contexts, and predict surgical weight loss. These tasks could be useful for individual assessment of expectations of amounts that are eaten in health and disease and for prediction of weight loss.

Which strategies to manage problem foods were related to weight loss in a randomized clinical trial?

Individuals managing their weight are often faced with problem foods that are difficult to resist eating. In the context of a weight-loss intervention, we characterized the most commonly reported problem foods and the behavioral strategies used to manage them, and examined which strategies were related to weight loss. Women with overweight and obesity (N = 186) participated in a one-year randomized trial of three interventions (NCT01474759): standard advice to eat less food, choosing portions based on energy density, and using pre-portioned foods. At Months 0, 6, and 12 of the trial, participants listed the foods they found most problematic and reported the frequency of using eight behavioral strategies to control intake of these foods, including three practices for avoiding exposure to problem foods and three for consuming them but limiting intake. The responses showed that 82% of the top three problem foods were in the categories of sweet baked items, salty snacks, starchy side dishes, chocolate and candy, and ice cream. After one year, women who reported more frequently using the strategy of limiting portions of problem foods had a greater rate of weight loss (kg/week), regardless of their intervention group (p < 0.0001). Among women who limited portions of problem foods less frequently, those using pre-portioned foods had greater initial weight loss compared to the other two groups, but then regained weight at a greater rate (p < 0.0001). The three avoidance strategies for problem foods were reported to be frequently used but were not found to be related to weight loss. These results suggest that adopting and maintaining strategies to manage portions of problem foods, rather than avoiding exposure to them, can be a more useful approach for weight loss.

Effects of snack portion size on anticipated and experienced hunger, eating enjoyment, and perceived healthiness among children

BACKGROUND

Large portion sizes encourage overconsumption. Prior studies suggest that this may be due to errors in anticipating the effects of portion size, although the studies were limited to adults and energy-dense foods.

OBJECTIVE

Our aim was to investigate potential anticipation errors related to the effects of portion size on hunger, eating enjoyment, and healthiness ratings among 8-to-11-year-old children, for snacks differing in energy density and healthiness perception, and as a function of initial hunger.

METHODS

In a within-subject design, 83 children aged 8 to 11 years old were first asked to anticipate how much they would enjoy, how hungry they would feel after eating, and how healthy it would be to eat a recommended serving size, a 50% larger portion, and a 125% larger portion of brownie or applesauce. Over six subsequent sessions, the children were asked to eat all of each of these portions and then rate their post-intake enjoyment, residual hunger, and healthiness perceptions. We also measured hunger at the beginning of each session.

RESULTS

For both snacks, larger portions reduced anticipated and experienced residual hunger similarly. In contrast, larger portions increased anticipated but not experienced eating enjoyment for both snacks; although larger portions increased anticipated and experienced enjoyment ratings among extremely hungry children. All children under-anticipated how much they would enjoy the smaller portion sizes. Healthiness ratings were unaffected by portion size for both snacks but differed across foods (applesauce vs. brownie).

CONCLUSIONS

Children anticipate the effects of portion size on hunger change accurately, overestimate the effects of portion size on eating enjoyment, and rate food healthiness on food type and not portion size. Helping children better anticipate the enjoyment from smaller (recommended) portion sizes and understand that food quantity, not just quality, matters for healthy eating may be a solution to improve portion control.

The (bitter) sweet taste of nudge effectiveness: The role of habits in a portion size nudge, a proof of concept study

Seemingly insignificant daily practices, such as sugar usage in tea, can have a great accumulated impact on societal issues, such as obesity. That is why these behaviours are often the target of nudge interventions. However, when these behaviours are performed frequently they may turn into habits that are difficult to change. The aim of the current study was to investigate whether a portion size nudge has the potential to work in accordance with (instead of against) existing habits. Specifically, it was tested whether a portion size nudge would be more effective in reducing the amount of sugar added to tea, when people have a strong habit of adding a fixed amount of teaspoons of sugar to a cup of tea. The study (N = 123) had a mixed factorial design with teaspoon size (reduced size vs. control) as a within-subject factor, and habit disruption context condition (hot tea vs. cold tea) as a between-subjects factor. A paired t-test indicated that this nudge reduced sugar intake on average by 27% within subjects. When the context allowed for automatic enactment of the habit, the effectiveness of this nudge was moderated by habit strength. Surprisingly, the nudge effect was actually less pronounced when people had a strong habit. Implications for effective nudge interventions are discussed.

Reductions to main meal portion sizes reduce daily energy intake regardless of perceived normality of portion size: a 5 day cross-over laboratory experiment

BACKGROUND

Smaller portions may help to reduce energy intake. However, there may be a limit to the magnitude of the portion size reduction that can be made before consumers respond by increasing intake of other food immediately or at later meals. We tested the theoretical prediction that reductions to portion size would result in a significant reduction to daily energy intake when the resulting portion was visually perceived as 'normal' in size, but that a reduction resulting in a 'smaller than normal' portion size would cause immediate or later additional eating.

METHODS

Over three 5-day periods, daily energy intake was measured in a controlled laboratory study using a randomized crossover design (N = 30). The served portion size of the main meal component of lunch and dinner was manipulated in three conditions: 'large-normal' (747 kcal), 'small-normal' (543 kcal), and 'smaller than normal' (339 kcal). Perceived 'normality' of portion sizes was determined by two pilot studies. Ad libitum daily energy intake from all meals and snacks was measured.

RESULTS

Daily energy intake in the 'large-normal' condition was 2543 kcals. Daily energy intake was significantly lower in the 'small-normal' portion size condition (mean difference - 95 kcal/d, 95% CI [- 184, - 6], p = .04); and was also significantly lower in the 'smaller than normal' than the 'small-normal' condition (mean difference - 210 kcal/d, 95% CI [- 309, - 111], p < .001). Contrary to predictions, there was no evidence that the degree of additional food consumption observed was greater when portions were reduced past the point of appearing normal in size.

CONCLUSIONS

Reductions to the portion size of main-meal foods resulted in significant decreases in daily energy intake. Additional food consumption did not offset this effect, even when portions were reduced to the point that they were no longer perceived as being normal in size.

TRIAL REGISTRATION

Prospectively registered protocol and analysis plan: https://osf.io/natws/; retrospectively registered: https://clinicaltrials.gov/ct2/show/NCT03811210.

Impact of bottle size on in-home consumption of wine: feasibility and acceptability randomised cross-over study

Background

Reducing alcohol consumption across populations would prevent many non-communicable diseases. Large packages increase food and non-alcoholic drink consumption and large glasses increase wine consumption. Smaller bottles may reduce alcohol consumption but their impact is uncertain. This study aims to (i) explore the feasibility and acceptability of conducting a large-scale randomised study to assess the impact of bottle size on in-home wine consumption and (ii) estimate the effect size and variance of the intervention on consumption to inform the design of future studies.

Methods

Cross-over randomised study in which 16 households in Cambridge, England, consuming at least two 750-ml bottles of wine each week, received a pre-set volume of wine biweekly for 4 weeks, in 750-ml and 375-ml bottles, in random order. Consumption was assessed by recording the number of empty and partially full bottles at the end of each biweekly period. At the end of the study, household representatives were interviewed about their experiences of participating in the study.

Results

The study procedures proved feasible. Comparable to similar trials, 14% of identified eligible households (18/125) consented to participate in the study. Attrition between consent and study completion was 11% (2/18) and 0% between study periods and 13% of households (2/16) correctly identified the study aim. The study procedures were considered acceptable. After adjusting for guest and out-of-home consumption, the difference in consumption between the 750-ml (3385.2 ml; SD = 1698.5) and 375-ml bottles (3376.7 ml; SD = 1719.0) was 8.4 ml (SD = 1235.4; 95%CI − 596.9, 613.8). Results suggest a possible order effect, with households receiving the 375-ml bottles first consuming more wine out of the 750-ml bottles and vice versa. This might also reflect an increase in consumption with study duration. Households receiving the 375-ml bottles first (6315.9 ml; SD = 3293.5) also drank less wine overall than those receiving the 750-ml bottles first (7335.4 ml; SD = 3735.4).

Discussion

The findings support the feasibility and acceptability of running a large-scale randomised study to assess the impact of bottle size on in-home wine consumption. Due to the heterogeneous patterning of results, a future study will be powered using the variance observed in the current study to detect a meaningful reduction of 250 ml of wine when consumed from smaller compared with larger bottles.

Trial registration

Open Science Framework (OSF): rmk43; May 23, 2017.

Improving the overall sustainability of the school meal chain: the role of portion sizes

PURPOSE

This work analyses the meal supply in primary schools in Italy to highlight new areas of inefficiency upstream of the food chain, regarding the size of the food portions specified in public tenders. A lack of conformity of food portions can potentially lead to a double negative externality affecting the sustainability of school meals: overweight children and food waste.

METHOD

Based on the data contained in the contract between municipalities and school catering services, the analysis was performed on the portion sizes (in grams) of the main food products included in the school menu for each regional capital (RC) in Italy. Data analysis regarded two main aspects: consistency of food portions within regions and adherence to national standards for childrens.

RESULTS

The results revealed great discrepancies amongst regions and in several cases, portion sizes significantly larger than the reference values of standard portions for school catering. The study also profiles RC on the basis of portion sizes, school meal attendance, and childhood obesity rates.

CONCLUSIONS

School meals have the potential to educate the next generation regarding healthy eating habits, and thus play a leading role in obesity prevention in children. Similarly, the educational role of eating at school can contribute to raising children's awareness about one of the most urgent environmental challenges-food waste-by introducing the best strategies for waste reduction, reuse, and recycling. Results have economic, social, health, and environmental implications and highlight the need to revisit policies to introduce new solutions for more sustainable and healthy school canteens in Italy.

LEVEL OF EVIDENCE

Level V, descriptive studies.

Mixed messages: Assessing interactions between portion-size and energy-density perceptions in different weight and sex groups

INTRODUCTION

Food portion size (PS) and energy density (ED) are the two primary determinants of total energy intake. While emerging neuroscientific data indicate judgments of PS and ED involve distinct brain regions, it is not understood how these judgements interact with each other to influence an individual's energy consumption. The present study investigated these cognitive interactions against body-mass-index (BMI) and sex.

METHODS

We tested 70 participants (including 34 overweight individuals) for cognitive biases when judging PS and ED, using the Garner task paradigm. Participants were asked to discriminate PS and ED, following pre-determined cognitive rules. Reaction time and correctness of their responses were recorded and analysed against the testing conditions across sexes and BMI groups.

RESULTS

We detected a significant 3-way interaction between BMI, Task, and Condition (F_{(3, 67)} = 4.1, p = 0.047, ƞ² = 0.06). Post-hoc tests suggested that, in the PS task, both weight groups experienced the Garner Interference effect introduced by variations of ED. That is, when making judgments concerning PS, participants were unable to ignore information relating to ED. Results from the ED task differed across weight groups, with only the overweight group being susceptible to the Garner Interference introduced by variations of PS. Additionally, both Sex and BMI were significant factors moderating reaction time when judging PS. Significantly longer reaction time was observed in female versus male comparisons, and for overweight versus healthy-weight participants (p < 0.05).

CONCLUSION

Overall, the results confirmed cognitive interactions involving PS and ED, although these interactions were asymmetric across BMI groups. These findings provide new insights into the cognitive processes underpinning individual dietary decision-making, and are potentially important for developing targeted intervention strategies for effective management of unhealthy eating behaviour.

Increasing the proportion of healthier foods available with and without reducing portion sizes and energy purchased in worksite cafeterias: protocol for a stepped-wedge randomised controlled trial

BACKGROUND

Overconsumption of energy from food contributes to high rates of overweight and obesity in many populations. A promising set of interventions tested in pilot studies in worksite cafeterias, suggests energy intake may be reduced by increasing the proportion of healthier - i.e. lower energy - food options available, and decreasing portion sizes. The current study aims to assess the impact on energy purchased of i. increasing the proportion of lower energy options available; ii. combining this with reducing portion sizes, in a full trial.

METHODS

A stepped-wedge randomised controlled trial in 19 worksite cafeterias, where the proportion of lower energy options available in targeted food categories (including main meals, snacks, and cold drinks) will be increased; and combined with reduced portion sizes. The primary outcome is total energy (kcal) purchased from targeted food categories using a pooled estimate across all sites. Follow-up analyses will test whether the impact on energy purchased varies according to the extent of intervention implementation.

DISCUSSION

This study will provide the most reliable estimate to date of the effect sizes of two promising interventions for reducing energy purchased in worksite cafeterias.

TRIAL REGISTRATION

The study was prospectively registered on ISRCTN (date: 24.05.19; TRN: ISRCTN87225572; doi: https://doi.org/10.1186/ISRCTN87225572).

Ratios of Food Amounts across Three Portion Size Categories on a Food Frequency Questionnaire in Men and Women

BACKGROUND

For some quantitative food frequency questionnaire (QFFQ) items, data may be insufficient to set gram weights for multiple portion size (PS) categories. Ratios of food amounts across PS categories may be used to quantify these PS for less frequently consumed food items.

OBJECTIVE

To explore the ratios of food amounts reported in 24-hour dietary recalls (24HDRs) by a sample of participants in a cohort study who chose the A (smallest) or C (largest) PS category on the QFFQ, relative to the food amounts for those who chose the B PS category.

DESIGN

This study was conducted as a cross-sectional design.

PARTICIPANTS/SETTING

Data were from participants (n=2,360) who completed three 24HDRs and the QFFQ in a calibration study of the Multiethnic Cohort Study in 1994-1997.

MAIN OUTCOME MEASURES

Median food amounts were calculated from 24HDRs for participants who selected each PS category (A, smallest; B; and C, largest) of items on the QFFQ. A-to-B and C-to-B ratios were computed if reported by five or more people in the 24HDRs: A-to-B ratios for 68 items (men) and 88 items (women); C-to-B ratios for 93 items (men) and 79 items (women).

STATISTICAL ANALYSES PERFORMED

The t test was used to compare the mean A-to-B ratios and C-to-B ratios as preset on the QFFQ with those from the 24HDRs and to examine sex differences. Analysis of variance was used to compare the mean ratios among race and ethnicity groups.

RESULTS

Mean A-to-B and C-to-B ratios were 0.71±0.15 and 1.45±0.35 in men and 0.71±0.15 and 1.44±0.40 in women based on the 24HDRs. Compared with the original QFFQ PS (A-to-B ratio=0.5±0.07; C-to-B ratio=1.8±0.30), the ratios were closer to 1 both in men and women (P<0.001). There were no significant sex differences or racial or ethnic differences.

CONCLUSIONS

These results provide guidance on appropriate ratios to use to set values for small and large PS categories on a QFFQ, particularly for items with insufficient information on usual PS.

Using pictorial nudges of fruit and vegetables on tableware to increase children's fruit and vegetable consumption

Children's fruit and vegetable consumption is lower than recommended. Increasing consumption is important for children's health. Nudges influence children's eating behaviour, but less is known about the influence of a pictorial nudge on tableware on children's fruit and vegetable consumption. Two studies examined this. Study 1 examined whether a pictorial fruit nudge (a grape image) on a plate influenced children's fruit (grape) consumption relative to a control condition (no image). In a between-subjects design, children (n = 63, Mean age = 8.9 years, SD = 1.41, 38 females, 25 males, 73% had a healthy-weight) were randomly assigned to one of two conditions (fruit nudge vs. control). Study 2 examined the influence of a large portion pictorial nudge (a large portion carrot image) vs. a small portion pictorial nudge (a small portion carrot image) vs. control (no nudge) on children's vegetable (carrot) consumption. In a between-subjects design, children (n = 59, Mean age = 8.57 years, SD = 2.13, 31 females, 28 males, 85% had a healthy-weight) were randomly assigned to a condition. In Study 1 children consumed significantly more fruit in the pictorial nudge condition than the control condition. In Study 2 children ate significantly more vegetables in the large portion pictorial nudge condition than the other two conditions. The small portion pictorial nudge did not affect children's vegetable consumption relative to control. The results indicate that pictorial nudges on tableware influence children's fruit and vegetable consumption, and the portion size of this type of nudge may be key to whether it influences children's eating behaviour.

Portion size normality and additional within-meal food intake: two crossover laboratory experiments

Reducing food portion size could reduce energy intake. However, it is unclear at what point consumers respond to reductions by increasing intake of other foods. We predicted that a change in served portion size would only result in significant additional eating within the same meal if the resulting portion size was no longer visually perceived as 'normal'. Participants in two crossover experiments (Study 1: n 45; Study 2: n 37; adults, 51 % female) were served different-sized lunchtime portions on three occasions that were perceived by a previous sample of participants as 'large-normal', 'small-normal' and 'smaller than normal', respectively. Participants were able to serve themselves additional helpings of the same food (Study 1) or dessert items (Study 2). In Study 1 there was a small but significant increase in additional intake when participants were served the 'smaller than normal' compared with the 'small-normal' portion (m difference = 161 kJ, P = 0·002, d = 0·35), but there was no significant difference between the 'small-normal' and 'large-normal' conditions (m difference = 88 kJ, P = 0·08, d = 0·24). A similar pattern was observed in Study 2 (m difference = 149 kJ, P = 0·06, d = 0·18; m difference = 83 kJ, P = 0·26, d = 0·10). However, smaller portion sizes were each associated with a significant reduction in total meal intake. The findings provide preliminary evidence that reductions that result in portions appearing 'normal' in size may limit additional eating, but confirmatory research is needed.

When a portion becomes a norm: Exposure to a smaller vs. larger portion of food affects later food intake

BACKGROUND

Portion sizes in the food environment may communicate information about what constitutes a 'normal' amount of food to eat. Here we examined whether mere visual exposure to a smaller vs. larger portion size of snack food affects perceptions of how much a 'normal' sized portion is and how much people choose to eat of that food in future.

METHODS

Under the guise of a study on taste preference and personality, 104 female participants were randomly allocated to be exposed to either a smaller or larger portion size of snack food. Twenty-four hours later participants freely selected a portion of the snack food to consume and reported on their perception of what constituted a normal sized portion of the snack food.

RESULTS

Participants that were exposed to a smaller, as opposed to larger portion size subsequently believed that a normal portion of the snack food was smaller in size. Exposure to the smaller as opposed to the larger portion size also resulted in participants consuming less snack food the next day.

CONCLUSIONS

Environmental exposure to smaller, as opposed to larger portion sizes of food may change perceptions of what constitutes a normal amount of food to eat and affect the amount of food people choose to eat in future.

Perceptions of tableware size in households of children and adolescents with obesity

PURPOSE

Portion size influences energy intake and is an important factor when developing weight management strategies. The effect of tableware on food intake is less clear, especially in children. To date, the relationship between the body weight of individuals and the tableware used in their households has not been investigated. The aim of this study was to analyze the sizes of tableware in households of children and adolescents with obesity (OBE) in comparison to participants with normal-weight matched for age and gender (NW).

METHODS

60 OBE (32 female, 26 male) and 27 NW (12 female, 15 male) aged between 9 and 17 years participated in a structured interview on the tableware used at home. Responses were standardized based on the selection of different sizes of tableware and everyday objects presented to the children.

RESULTS

In households of NW, larger plates and bowls were used during meals and desserts compared to OBE. OBE drank out of larger bottles. Shapes and sizes of drinkware, the number of children drinking out of bottles and the cutlery used during dessert did not differ between the groups.

CONCLUSIONS

Drinking out of large bottles may be an unfavourable habit of OBE if they contain sugar-rich liquids. The use of smaller plates and bowls of OBE may result in multiple helpings being consumed and so contribute to an overall increased portion size.

LEVEL OF EVIDENCE

Level V, Descriptive study.

Portion size and meal consumption in domesticated dogs: An experimental study

Increases in food portion sizes have been identified as a possible contributor to the increased prevalence of obesity in humans. However, little is known about the origin of behavioural tendencies to overeat from larger portion sizes or whether other non-human animals are affected by meal portion size. In the present experimental study, we examined the effect that larger portion sizes have on meal consumption among domesticated dogs (N = 32). Dogs were fed three meals that varied in size on different occasions (150%, 200% and 300% of usual portion size). A repeated measures design was used and food consumption was measured for each meal. Portion size positively affected food consumption, with dogs eating significantly more food as the portion size of meal increased. The effect of portion size on food consumption was also observed when the dogs that finished all available food were excluded from analyses, however not among dogs who did not finish any of the meals. We conclude that the influence larger portions have on food consumption observed in humans is also observed in domesticated dogs. However, it is unclear whether portion size directly biases the amount of food dogs choose to consume, as has been suggested in humans. Further research is now warranted to examine commonalities between human and non-human animal eating behaviour to understand shared behavioural tendencies and their origins.

Portion size effects vary: The size of food units is a bigger problem than the number

While it is well-known that larger food portions lead to increased consumption (i.e., the portion size effect), previous studies confound the effect of the size and the number of food units making up the larger portion. Moreover, empirical tests of the mechanism underlying the portions size effect are scarce. In response to these shortcomings, we present three experiments that test the impact of food unit-size and unit-number on consumption of increasingly large portion sizes, and assess whether perceptions of quantity (driven by unit size or number) mediate the portion size effect. Study 1 (n = 185), tracking actual consumption, shows that the portion size effect is determined more by unit-size than unit-number. Relative consumption ratios are higher when participants were served portions made up of enlarged food units compared to more food units. Since perceived quantity and consumption are thought to be negatively related, Study 2 (n = 193) reveals that consumers' quantity perceptions of portions are lower for unit-size (vs. unit-number) increases. Study 3 (n = 189) considers both perceived quantity and consumption and demonstrates that perceived quantity indeed mediates the effect of food portion size on consumption. Finally, this study also shows that encouraging consumers to focus perceptually on size when portion size increases are in terms of unit-size, or focus on number when portion size increases are in terms of unit-number, supports them in increasing quantity perceptions and decreasing actual consumption. Hence, manipulating the perceptual focus of consumers helps to mitigate the portion size effect. The findings contribute to literature on the portion size effect and numerosity heuristic, and provide practical insights on food packaging so to tackle the obesity crisis.

Food portion size influences accompanying beverage selection in adults

When trying to reduce food portion size, it is important that meal satisfaction is, as far as possible, preserved. Otherwise, individuals may select accompaniments to the meal (e.g., snacks, beverages) to achieve satisfaction and, in doing so, negate any benefit of the original portion size reduction. This study investigated whether varying portion sizes of food would influence choice of accompanying beverages. That is, when presented with a food portion size that is smaller or larger than their ideal, an individual may compensate by choosing a beverage based on its satiating and/or orosensory properties to balance the expected satiation and satisfaction of a meal. Data from an online interactive study (n = 93) was analysed using multilevel ordinal logistic regression models. Food portion size (100, 300, 500, 700, or 900 kcal) predicted beverage choice (water, low-energy sweetened beverage, high-energy sweetened beverage). For example, the sweetened beverages were more likely to be selected with small food portion sizes (p < .001). Participant ideal food portion size did not interact with this relationship. Participants appear to have recognised that sweetened beverages provide flavour and/or energy, and used them to compensate for a smaller meal. While switching to a low-energy beverage with an increased food portion size is advantageous for energy balance, choosing a high-energy beverage with a decreased food portion size is likely to be detrimental for those attempting to reduce energy intake and body weight.