Accuracy of energy and nutrient intake estimation versus observed intake using 4 technology-assisted dietary assessment methods: a randomized crossover feeding study

BACKGROUND

Technology-assisted 24-h dietary recalls (24HRs) have been widely adopted in population nutrition surveillance. Evaluations of 24HRs inform improvements, but direct comparisons of 24HR methods for accuracy in reference to a measure of true intake are rarely undertaken in a single study population.

OBJECTIVES

To compare the accuracy of energy and nutrient intake estimation of 4 technology-assisted dietary assessment methods relative to true intake across breakfast, lunch, and dinner.

METHODS

In a controlled feeding study with a crossover design, 152 participants [55% women; mean age 32 y, standard deviation (SD) 11; mean body mass index 26 kg/m2, SD 5] were randomized to 1 of 3 separate feeding days to consume breakfast, lunch, and dinner, with unobtrusive weighing of foods and beverages consumed. Participants undertook a 24HR the following day [Automated Self-Administered Dietary Assessment Tool-Australia (ASA24); Intake24-Australia; mobile Food Record-Trained Analyst (mFR-TA); or Image-Assisted Interviewer-Administered 24-hour recall (IA-24HR)]. When assigned to IA-24HR, participants referred to images captured of their meals using the mobile Food Record (mFR) app. True and estimated energy and nutrient intakes were compared, and differences among methods were assessed using linear mixed models.

RESULTS

The mean difference between true and estimated energy intake as a percentage of true intake was 5.4% (95% CI: 0.6, 10.2%) using ASA24, 1.7% (95% CI: -2.9, 6.3%) using Intake24, 1.3% (95% CI: -1.1, 3.8%) using mFR-TA, and 15.0% (95% CI: 11.6, 18.3%) using IA-24HR. The variances of estimated and true energy intakes were statistically significantly different for all methods (P < 0.01) except Intake24 (P = 0.1). Differential accuracy in nutrient estimation was present among the methods.

CONCLUSIONS

Under controlled conditions, Intake24, ASA24, and mFR-TA estimated average energy and nutrient intakes with reasonable validity, but intake distributions were estimated accurately by Intake24 only (energy and protein). This study may inform considerations regarding instruments of choice in future population surveillance. This trial was registered at Australian New Zealand Clinical Trials Registry as ACTRN12621000209897.

Role of Portion Size in the Context of a Healthy, Balanced Diet: A Case Study of European Countries

Over the past decades, a generalised increase in food portion sizes has probably contributed to the growing global obesity epidemic. Increasing awareness of appropriate portion sizes could contribute to reversing this trend through better control of calorie intake. In this study, a comparison of standard portion sizes in European countries for various food categories shows a wide variability of their importance for food, nutrient, and energy consumption according to government and institutional websites. On the other hand, the overall averages appear to be largely in line with the values indicated by the Italian Society of Human Nutrition, which is the most comprehensive and detailed document among those evaluated. The exceptions are milk and yoghurt, for which the reference portions in Europe are generally higher, and vegetables and legumes, for which portions are smaller than those reported in the Italian document. Moreover, the portion sizes of staple foods (e.g., pasta and potatoes) vary according to different food traditions. It is reasonable to consider that the creation of harmonised standard reference portions common to the European countries, based on international guidelines and scientific evidence, would significantly contribute to consumers' nutritional education and ability to make informed choices for a healthy diet.

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.

Multisectoral Strategies Needed to Establish Healthy Portion Size Norms That Disincentivize Hyperpalatable, Energy-Dense Foods and Sugary Beverages in Food Environments Linked to Obesity and Diet-Related Chronic Diseases in the United States

Over 40 y, Americans have consumed larger portions of hyperpalatable, energy-dense foods, sugary beverages, and meals prepared at home and away from home, which have contributed to obesity and diet-related chronic diseases in the United States (US). This perspective article explores synergies between the portion size and food matrix effects, and their associated biological, physiological, environmental, and cultural susceptibilities for populations. Thereafter, we describe evidence of US public- and private-sector initiatives to reduce, standardize, and incentivize portion size norms to align with recommended servings to promote a healthy weight for children, adolescents, and adults. Practitioners could use the Individual plus Policy, System, and Environment (I + PSE) Framework to implement multisectoral strategies for the US government, businesses, and civil society organizations to establish healthy portion size norms aligned with servings recommended by the Dietary Guidelines for Americans 2020-2025, and to disincentivize overconsumption of hyperpalatable products to reduce obesity and chronic disease risks.

Development and validation of a new methodological platform to measure behavioral, cognitive, and physiological responses to food interventions in real time

To fully understand the causes and mechanisms involved in overeating and obesity, measures of both cognitive and physiological determinants of eating behavior need to be integrated. Effectively synchronizing behavioral measures such as meal micro-structure (e.g., eating speed), cognitive processing of sensory stimuli, and metabolic parameters, can be complex. However, this step is central to understanding the impact of food interventions on body weight. In this paper, we provide an overview of the existing gaps in eating behavior research and describe the development and validation of a new methodological platform to address some of these issues. As part of a controlled trial, 76 men and women self-served and consumed food from a buffet, using a portion-control plate with visual stimuli for appropriate amounts of main food groups, or a conventional plate, on two different days, in a random order. In both sessions participants completed behavioral and cognitive tests using a novel methodological platform that measured gaze movement (as a proxy for visual attention), eating rate and bite size, memory for portion sizes, subjective appetite and portion-size perceptions. In a sub-sample of women, hormonal secretion in response to the meal was also measured. The novel platform showed a significant improvement in meal micro-structure measures from published data (13 vs. 33% failure rate) and high comparability between an automated gaze mapping protocol vs. manual coding for eye-tracking studies involving an eating test (ICC between methods 0.85; 90% CI 0.74, 0.92). This trial was registered at Clinical Trials.gov with Identifier NCT03610776.

Relationship between front-of-pack labeling and nutritional characteristics of food products: An attempt of an analytical approach

The adoption of supplementary nutrition information, i.e., front-of-pack labeling (FOPL), on pre-packed food products is advocated as a tool to improve the consumers' knowledge of the nutrient content or the nutritional quality of foods, but also to drive products reformulation by the food industry. Ultimately, FOPL should help people to select foods in order to compose an overall balanced diet, which is essential for health. However, the extent to which the different FOPL systems proposed in the European Union (EU) (interpretative or informative) are effectively able to convey the information useful to improve both food choices and dietary habits of the consumers is still under debate and needs to be analyzed in detail. The use of 3 FOPL schemes proposed within the EU (Nutri-Score, Keyhole and NutrInform Battery) to compare products available on the Italian market within different food categories, highlights some critical issues: (1) different FOPL provide to consumers different kinds of information; (2) systems based on similar theoretical approaches can provide conflicting information; (3) the algorithms on which interpretative FOPL are based can give the same summary information for products differing in nutrient composition, impact on the overall dietary balance and therefore on the health of people with different characteristics, physiological/pathological conditions, and nutritional requirements; (4) on the other hand, products with similar nutrient composition can obtain different interpretative FOPL; (5) informative systems are generally more complex and require greater both attention and knowledge from the consumer; (6) FOPL based on 100 g of product overlook the role of portion (and frequency of consumption) in determining the nutrient intake without informing on the contribution of a single food to the overall diet; (7) FOPL based on scoring systems could promote the reformulation of selected products, especially with a composition very close to the threshold limits; (8) for the portion-based informative FOPL systems, the incentive for reformulation could essentially involve the reduction of portion size. Finally, the importance of nutritional education interventions, which are required to encourage the use by consumers of informative FOPL systems, cannot be neglected to improve the quality of diets regardless of the FOPL used.

Sugar Content and Warning Criteria Evaluation for Popular Sugar-Sweetened Beverages in Taipei, Taiwan

Sugar intake may increase the risk of obesity, cardiovascular disease, diabetes, and dental caries. In Taiwan, people frequently consume sugar-sweetened beverages (SSBs). This study explored the energy and sugar content of Taiwanese SSBs and evaluated them using the Chilean warning label system (>70 kcal/100 mL and >5 g sugar/100 mL) and the World Health Organization (WHO) sugar guideline (≤25 g sugar). A total of 341 SSBs with volumes ≤600 mL were analyzed. No significant differences were observed in sugar per serving among different types of SSBs, but a great variation in portion size (i.e., package size for individual consumption) was noted. The energy and sugar ratios per serving were lower in soft drinks and coffee and tea containing >1 serving than in those containing only one serving. The calorie and sugar ratios per portion were higher in all types of SSBs containing >1 serving per portion than in those containing exactly one serving. Approximately 70.0% of Taiwanese SSBs were classified as high sugar according to the Chilean criteria, and 41.6% of SSBs exceeded the WHO guideline. Moreover, 40.8% of SSBs that were not considered as high sugar according to the Chilean criteria contained >25 g sugar per portion. For individual consumption, it is more clear that nutrition labeling is based on portion rather than serving. Evaluating SSBs on sugar/portion rather than sugar/100 mL will help consumers make better choices.

Acceptability, Usability and Weight Loss Outcomes in a Randomized Cross-Over Study of Commercially Available Portion Size Tools in an Overweight South Asian Community

South Asian women living in the UK are particularly at high risk of obesity-related complications, such as type 2 diabetes and cardiovascular disease. Exposure to large portion sizes is a risk factor for obesity. Specifically designed tableware helps individuals to manage weight by controlling food portion sizes. Thirty-one (n = 31) overweight or obese South Asian adult women participated in a randomised cross-over trial aimed to assess the efficacy, acceptance, and weight change of two guided/calibrated commercially available portion control tools (Utensil set and Crockery Set) used in free-living conditions. Data on acceptance, perceived changes in portion size, frequency, and meal type was collected using paper questionnaires and 3-day diet diaries. Scores describing acceptance, ease of use, and perceived effectiveness were derived from five-point Likert scales from which binary indicators (high/low) were analysed for significance using multivariate variance analysis for repeated measurements. A reduction in BMI was observed at each point of measurement (p = 0.007). For overall tool use, the crockery set scored higher in all areas of acceptance, ease of use, and perceived efficacy for all comparisons. Self-selected portion sizes increased for salads and decreased for cooking oil and breakfast cereals with both tools. Further research to scale up and evaluate similar weight management interventions for this group is warranted.

The Use of Portion Control Plates to Promote Healthy Eating and Diet-Related Outcomes: A Scoping Review

The role of portion control plates in achieving healthy diets is unclear. The aim of this scoping review was to systematically map findings from peer reviewed and grey literature to provide evidence for the use of portion control plates to promote healthy eating and nutrition-related knowledge in children and adults. A secondary aim was to review the design characteristics of portion control plates. The search was conducted in four databases, including Medline, CINAHL, Embase, and PsycInfo, and grey literature sources following the PRISMA scoping review guidelines. A total of 22 articles comprising 23 intervention studies and 8 from grey literature were included. It was found that the various two-dimensional and three-dimensional portion control plates examined were effective tools for better portion size selection in healthy children and adults. Most portion control plates dedicated half the plate to vegetables, a quarter to protein, and a quarter to carbohydrates. The use of portion control plates in nutrition interventions appears to promote weight loss among those with overweight and obesity and/or type 2 diabetes. However, portion control plates were mostly used as part of multicomponent interventions and the effectiveness of the portion control plate as a stand-alone educational resource or portion control tool alone was uncertain. Further interventional research is indicated to investigate portion plates as tools to improve dietary behaviours and food consumption at the population level.

The Effect of Downsizing Packages of Energy-Dense, Nutrient-Poor Snacks and Drinks on Consumption, Intentions, and Perceptions-A Scoping Review

The single-serve packaging of discretionary foods is becoming increasingly popular, but evidence is limited on whether smaller package sizes can reduce food intake. The aim of this scoping review is to assess the effect of reducing the package size of energy-dense, nutrient-poor (EDNP) snacks and drinks on consumption, intentions, and perception, and to examine the effects of potential moderators or mediators. The search was conducted in six selected databases and grey literature sources, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for the scoping review process (PRISMA-ScR) guidelines. After screening 5562 articles, 30 articles comprising 47 intervention studies were included. Twelve of 15 studies found a significant effect in lowering the actual or intended consumption when a single smaller package was offered compared with a single larger package. When the total serving size was held constant between varying package conditions, such as a multipack, single package, or unpackaged, the results on the actual and intended consumption were inconsistent and varied according to the presence of moderators. Overall, these findings suggest that an overall reduction in the size of a single package is a more promising strategy than providing multipacks to reduce consumption. Changes to the current food environment to promote single smaller packages of EDNP snacks and drinks are necessary to support the better selection of appropriate portion sizes and reduce consumption.

Sugar Content of Market Beverages and Children's Sugar Intake from Beverages in Beijing, China

(1) Background: This study aims to find the sugar content of market beverages and estimate the sugar intake from beverages among students in Beijing. (2) Methods: Using snapshotting, we collected the sugar content of beverages through their packages or nutrition labels. Combined with the statistic of student beverage consumption, we estimated students' sugar intake. (3) Results: The median sugar content of total beverages was 9.0 g/100 mL, among which the fruits/vegetable juices and beverages had the highest sugar content (10.0 g/100 mL). Sugar content in most beverages in Beijing was generally higher than the recommendations, and fruit/vegetable juices and beverages exceeded the most. The median of sugar intake from beverages among students was 5.3 g/d, and the main sources were fruit/vegetable juices and beverages, protein beverages and carbonated beverages. Sugar intake from beverages differed according to gender, age and living area. Higher sugar intake was found among boys, older students and rural students. (4) Conclusions: Sugar content in market beverages in Beijing were high. Gender, age and residence were the influencing factors of sugar intake. Targeted measures should be taken to decrease the sugar content in beverages, especially the fruit/vegetable juices and beverages and the sugar intake among students.

Size and shape of plates and size of wine glasses and bottles: impact on self-serving of food and alcohol

Background

The physical properties of tableware could influence selection and consumption of food and alcohol. There is considerable uncertainty, however, around the potential effects of different sizes and shapes of tableware on how much food and alcohol people self-serve. These studies aimed to estimate the impact of: 1. Plate size and shape on amount of food self-served; 2.Wine glass and bottle size on amount of wine self-poured.

Methods

140 adults participated in two laboratory studies—each using randomised within-subjects factorial designs—where they self-served food (Study 1) and wine (Study 2):

Study 1: 3 plate sizes (small; medium; large) × 2 plate shapes (circular; square).

Study 2: 3 wine glass sizes (small; medium; large) × 2 wine bottle sizes (75 cl; 50 cl).

Results

Study 1: There was a main effect of plate size: less was self-served on small (76 g less, p < 0.001) and medium (41 g less, p < 0.001) plates, compared to large plates. There was no evidence for a main effect of plate shape (p = 0.46) or a size and shape interaction (p = 0.47).

Study 2: There was a main effect of glass size: less was self-served in small (34 ml less, p < 0.001) and medium (17 ml less, p < 0.001) glasses, compared to large glasses. There was no evidence of a main effect of bottle size (p = 0.20) or a glass and bottle size interaction (p = 0.18).

Conclusions

Smaller tableware (i.e. plates and wine glasses) decreases the amount of food and wine self-served in an initial serving. Future studies are required to generate estimates on selection and consumption in real world settings when numerous servings are possible.

Protocol registration information: OSF (https://osf.io/dj3c6/) and ISRCTN (10.1186/ISRCTN66774780).

Supplementary Information

The online version contains supplementary material available at 10.1186/s40359-021-00645-z.

Food intake in children and adolescents: a cross-sectional study from 2009/2010 to 2015/2016

The aim was to describe food intake over time in children and adolescents, with respect to age and gender. The present study was a repeated cross-sectional study using self-reported data from a health questionnaire. Data were collected from the School Health Services in south-east Sweden from 44 297 students, 10, 13–14 and 16 years of age, 48 % girls and 52 % boys from 2009/2010 to 2015/2016. Reported intakes for eight foods were analysed in relation to the Nordic Nutrition Recommendations. Seventeen per cent of the students reported an intake in line with the recommendations for at least six of the eight foods fish, vegetables, fruit, mealtime beverages, juice/chocolate drinks, sugar-sweetened beverages, sweets/snacks and pastries. Intake of at least two fruits a day was the recommendation that was followed by the lowest proportion of students (30 %), and this result was stable over the study period. There was a gradual increase over time in the proportion of students who reported an intake in line with the recommendations. Younger students compared to older students, as well as girls compared to boys, reported intakes in line with the recommendations to a statistically significant larger extent. Few students reported intakes in line with the recommendations, although the quality of food intake seems to improve over time. The present results indicate a deterioration in reported food intake in the early years of adolescence. Finding methods to support all children and especially older adolescents to eat healthier, including eating more fruit, is of great importance to public health.

Impact of Portion Control Tools on Portion Size Awareness, Choice and Intake: Systematic Review and Meta-Analysis

Portion control utensils and reduced size tableware amongst other tools, have the potential to guide portion size intake but their effectiveness remains controversial. This review evaluated the breadth and effectiveness of existing portion control tools on learning/awareness of appropriate portion sizes (PS), PS choice, and PS consumption. Additional outcomes were energy intake and weight loss. Published records between 2006–2020 (n = 1241) were identified from PubMed and WoS, and 36 publications comparing the impact of portion control tools on awareness (n = 7 studies), selection/choice (n = 14), intake plus related measures (n = 21) and weight status (n = 9) were analyzed. Non-tableware tools included cooking utensils, educational aids and computerized applications. Tableware included mostly reduced-size and portion control/calibrated crockery/cutlery. Overall, 55% of studies reported a significant impact of using a tool (typically smaller bowl, fork or glass; or calibrated plate). A meta-analysis of 28 articles confirmed an overall effect of tool on food intake (d = –0.22; 95%CI: –0.38, –0.06; 21 comparisons), mostly driven by combinations of reduced-size bowls and spoons decreasing serving sizes (d = –0.48; 95%CI: –0.72, –0.24; 8 comparisons) and consumed amounts/energy (d = –0.22; 95%CI: –0.39, –0.05, 9 comparisons), but not by reduced-size plates (d = –0.03; 95%CI: –0.12, 0.06, 7 comparisons). Portion control tools marginally induced weight loss (d = –0.20; 95%CI: –0.37, –0.03; 9 comparisons), especially driven by calibrated tableware. No impact was detected on PS awareness; however, few studies quantified this outcome. Specific portion control tools may be helpful as potentially effective instruments for inclusion as part of weight loss interventions. Reduced size plates per se may not be as effective as previously suggested.

People serve themselves larger portions before a social meal

One of the most powerful influences on food intake yet identified is the presence of familiar others at an eating occasion: people eat much more when they eat with friends/family than when they eat alone. But why this is the case is unclear. Across two studies (Study 1: N = 98; Study 2: N = 120), we found that the mere anticipation of social interaction is all that is needed to promote the selection of larger meals, and that this occurs even when a person is alone when they make their decision. Adult women served themselves larger portions when they knew they were going to eat socially versus when they knew they were going to eat alone. These data suggest that how other people influence our food intake reaches beyond the specific eating context to affect pre-meal portion size decisions, suggesting that a fundamental shift is required in our thinking about social influences on eating.

Development of a Simplified Portion Size Selection Task

Portion size is an important determinant of energy intake and the development of easy to use and valid tools for measuring portion size are required. Standard measures, such as ad libitum designs and currently available computerized portion selection tasks (PSTs), have several limitations including only being able to capture responses to a limited number of foods, requiring participants’ physical presence and logistical/technical demands. The objective of the current study was to develop and test robust and valid measures of portion size that can be readily prepared by researchers and be reliably utilized for remote online data collection. We developed and tested two simplified PSTs that could be utilized online: (1) portion size images presented simultaneously along a horizontal continuum slider and (2) multiple-choice images presented vertically. One hundred and fifty participants (M = 21.35 years old) completed both simplified PSTs, a standard computerized PST and a series of questionnaires of variables associated with portion size (e.g., hunger, food item characteristics, Three Factor Eating Questionnaire). We found average liking of foods was a significant predictor of all three tasks and cognitive restraint also predicted the two simplified PSTs. We also found significant agreement between the standard PST and estimated portion sizes derived from the simplified PSTs when accounting for average liking. Overall, we show that simplified versions of the standard PST can be used online as an analogue of estimating ideal portion size.

Trends in Sales and Industry Perspectives of Package Sizes of Carbonates and Confectionery Products

Discretionary food package sizes are an important environmental cue that can affect the amount of food consumed. The aim of this study was to determine sales trends and reported food industry perspectives for changing food package sizes of carbonates and confectionery between 2005 and 2019. Changes in package sizes of carbonates and confectionery were investigated in Australia, the USA, Canada, and the UK. Sales data (units per capita and compound annual growth rate between 2005 and 2019) were extracted from the Euromonitor database. Qualitative data (market research reports) on industry perspectives on package size changes were extracted from industry and marketing databases. Carbonate sales data showed increased growth of smaller package sizes (<300 mL) and a decrease in sales of larger package sizes (≥2000 mL) in all four countries. In contrast, confectionery sales data showed no consistent trends across the selected countries. No growth was observed for smaller confectionery package sizes but an increase in growth of larger package sizes (50–99 g, >100 g), including share packages, was observed in Australia. Qualitative data (n = 92 articles) revealed key reasons identified by industry for changes in package size related to consumer health awareness, portion size control, convenience, market growth, and government or industry initiatives. Monitoring of discretionary food package sizes provides additional insights into consumers’ food environment.

Out of the lab and into the wild: The influence of portion size on food intake in laboratory vs. 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.

Portion-control intervention for people with serious mental illness: A feasibility study

PURPOSE

Portion control can be an effective weight-loss strategy for people with serious mental illnesses (SMI). This study aimed to examine the feasibility of portion-control intervention (PCI) for people with SMI.

DESIGN AND METHODS

A randomized experimental design was used. The PCI group received weekly, telephone-delivered behavioral counseling over 12 weeks. Newsletter group received monthly newsletters regarding healthy eating. Descriptive statistics were used to analyze data collected at baseline and at 12 weeks.

FINDINGS

The acceptability of the PCI and significant decreases in waist circumference among the participants of the PCI group were reported.

PRACTICE IMPLICATIONS

Simple and structured guidelines to manage portion size, akin to those featured in our PCI, can benefit those with SMI.

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).

Exploring the Experiences of People with Obesity Using Portion Control Tools-A Qualitative Study

Large portion sizes increase consumption and eating smaller portions is recommended as a weight control strategy. However, many people report difficulties enacting this advice. This study examined the experience of individuals using two commercially available portion-control tools to try to manage their weight. In a crossover design, 29 adults with obesity (18 women) who had attended a previous weight loss intervention in the community were invited to use two portion-control tool sets over a period of four weeks (two weeks each) and to complete a semi-structured questionnaire about their experience. The tools were a guided crockery set (sector plate, calibrated bowl, and calibrated glass) and a set of calibrated serving spoons (one for starch, one for protein, and one for vegetables). Data were analyzed using thematic framework analysis. A key theme was related to the educational benefits of the tools, such as generating awareness, guidance, and gaining an independent ability to judge appropriate portions. Other key themes were tool usability, acceptability, and feasibility of usage. Barriers identified by participants included unclear markings/instructions and the inconvenience of using the tool when eating away from home. Overall, the tools were perceived to be educationally useful, easy to use, and potentially effective for learning to control portions, which suggested that these instruments could help in weight management interventions alongside other strategies. Elements of the tool design could influence the ability of participants to adhere to using the tool, and hence allow the educational effect to be mediated.