What is the role of portion control in weight management?

The effect of discretionary snack consumption on overall energy intake, weight status, and diet quality: A systematic review

The consumption frequency and portion size of discretionary snacks are thought to contribute to a greater food intake and risk of overweight or obesity in the developed world but evidence from epidemiological studies is inconclusive. To investigate this, we systematically evaluated evidence on the effects of discretionary snack consumption on weight status, energy intake, and diet quality. Articles involving discretionary snacks reported against the outcome measures of any primary, peer-reviewed study using human participants from free-living conditions for all age groups were included. A total of 14,780 titles were identified and 40 eligible publications were identified. Three key outcomes were reported: weight status (n = 35), energy intake (n = 11), and diet quality (n = 3). Increased discretionary snack consumption may contribute modestly to energy intake, however, there is a lack of consistent associations with increased weight/BMI. Although cross-sectional analyses offered conflicting findings, longitudinal studies in adults showed a consistent positive relationship between discretionary snack intake and increasing weight or body mass index. Given that experimental findings suggest reducing the size of discretionary snacks could lead to decreased consumption and subsequent energy intake, food policy makers and manufacturers may find it valuable to consider altering the portion and/or packaging size of discretionary snacks.

Diet and exercise knowledge and practices for diabetes care within families in Senwabarwana

BACKGROUND

 Family members (FMs) are a valuable source of support, as the bulk of daily diabetes treatment occurs at home. Family members' insufficient understanding of patient support can lead to poor diabetes outcomes. Lack of knowledge about good diet and exercise can lead to unhealthy food preparation and sedentary lifestyles, affecting patients and increasing the risk of diabetes. This study aims to fill the gap in the level of knowledge of FMs relating to appropriate care for diabetic patients under their care. This will relate specifically to diet and exercise.

METHODS

 A cross-sectional survey conducted in Senwabarwana, Limpopo province, involved 200 FMs caring for diabetic patients for at least 6 months. Their experience could offer valuable insights into the competence of their care. Data were collected regarding knowledge and practice using a close-ended questionnaire, with Likert scale responses and SPSS analysis, including descriptive statistics and chi-squared tests. Knowledge was assessed on a scale ranging from poor to excellent: poor (0% - 50%), fair (51% - 60%), good (61% - 74%) and excellent ( 75%). Practice was assessed as poor (0% - 50%), fair (51% - 69%) and good (70% - 100%).

RESULTS

 Thirty-one percent of participants demonstrated excellent knowledge and only 9% demonstrated good practice. Unfortunately, 53% stated that obese patients with diabetes should skip meals to lose weight. Only 3.5% and 19%, respectively, are familiar with recommendations for exercise and glucose monitoring. Barely 35.5% of FMs eat breakfast every day, while 87.5% report exercising.

CONCLUSION

 Few FMs possess excellent diabetes management knowledge but still indulge in bad practices, increasing their risk of developing diabetes. Additionally, they may potentially cause health problems for patients.Contribution: Family-centred behaviour change intervention is recommended.

An exploration of customers' perceptions, preferences, experiences, and feasibility of offering standardized portions in restaurants

Excess caloric intake increases the risk of weight gain, and diet-related chronic diseases. Restaurants play an integral role in the portions of food people consume. Standardization of portion sizes in restaurants can help customers recognize appropriate portions. Through customer interviews, we aimed to assess and understand the feasibility, perceptions, and acceptability of standardized portions in restaurants. Kaiser Permanente partnered with three restaurants in Southern California to create alternative menu options of meals that would not exceed 700 calories. Kaiser Permanente members who lived within a 5-mile radius of the restaurants were informed through email about the study. Customers (N=33), who dined at one of the restaurants participated in a one-on-one semi-structured interview. Interviews were recorded, typed, transcribed verbatim, and analyzed using thematic analysis. Four themes emerged from the analysis: 1) Customers perceive standard portions as a better choice and the benefits outweigh regular portions; 2) Individual and restaurant-related factors may influence portion preferences; 3) Restaurant portions are perceived to be in excess of what customers need; and 4) Portion standardization is an evolving area for restaurants. Our findings suggest positive perceptions and acceptance of standardized portions among restaurant customers. Customer awareness and restaurant standardization procedures can improve customers' dining experience.

Uncovering the Cardiovascular Threat: A Comprehensive Examination of Liver Fibrosis and Subclinical Atherosclerosis in Non-alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) has emerged as a global epidemic intricately linked to the rising tide of obesity and metabolic syndrome. This comprehensive review delves into the complex web of relationships between NAFLD, liver fibrosis, and subclinical atherosclerosis, shedding light on their interplay, shared risk factors, and clinical implications. NAFLD encompasses a spectrum of liver conditions, from the benign non-alcoholic fatty liver (NAFL) to the more severe non-alcoholic steatohepatitis (NASH), characterized by inflammation and hepatocellular injury. Central to the discussion is the insidious development of liver fibrosis, the ominous harbinger of progressive liver damage, cirrhosis, and hepatocellular carcinoma. The increasing prevalence of NAFLD, now affecting a quarter of the global population, poses a significant public health challenge. Its association with obesity, insulin resistance, and metabolic syndrome highlights the multifactorial nature of this disease. However, NAFLD's repercussions extend beyond the liver. This review unveils a potent connection between NAFLD and subclinical atherosclerosis, the early precursor to cardiovascular disease. Individuals with NAFLD face an elevated risk of atherosclerosis, even without traditional cardiovascular risk factors. The intricate link between these two conditions is illuminated through shared pathophysiological pathways, including systemic inflammation, insulin resistance, and dyslipidemia. Understanding the interplay between liver fibrosis and subclinical atherosclerosis has profound clinical implications. Patients with advanced fibrosis or cirrhosis are not only at risk of liver-related complications but also of cardiovascular events. This necessitates a holistic approach to patient care, with lifestyle modifications and pharmacological interventions simultaneously managing both conditions. Physicians must prioritize early detection and collaborate across disciplines to provide comprehensive care. Looking ahead, the future holds promising avenues of research. Emerging areas include genetics and precision medicine, microbiome research, and epigenetics, which may unveil new therapeutic targets. Innovations in diagnostics and therapeutics, such as non-invasive biomarkers and combination therapies, offer hope for more effective management. Long-term outcomes and survivorship research will provide insights into the lasting impact of interventions. In conclusion, this review underscores the imperative of addressing liver fibrosis and atherosclerosis in the context of NAFLD. It is a call to action for healthcare professionals, researchers, and policymakers to work collaboratively, promote early detection, and advance our understanding of these interconnected conditions. By doing so, we can enhance patient outcomes and chart a course toward a healthier future for those grappling with NAFLD and its intricate web of consequences.

Nutrition knowledge and influence on diet in the carer-client relationship in residential care settings for people with intellectual disabilities

People with intellectual disabilities generally have poorer health outcomes compared with those who do not, including outcomes related to nutrition-related non-communicable diseases. Carers support people with intellectual disabilities in many aspects including habitual shopping and preparation of food, but their own nutrition knowledge and the influence this may have on dietary intakes of clients is unknown. We explored the nutrition knowledge of carers of people with intellectual disabilities in residential care settings, their dietary habits and their influence on clients' food shopping and preparation and therefore the diet consumed by their clients. Ninety-seven carers belonging to a large independent care sector organisation specialising in the care of people with an intellectual disability completed a validated general nutrition knowledge and behaviour questionnaire. Seventeen carers from the residential care settings were interviewed to contextualise practice. Knowledge about key dietary recommendations scored highly. Carers who had more work experience were found to have higher scores in 'making everyday food choices' (p = 0.034). Daily consumption of fruit and vegetables (at least one portion per day) was observed (for fruit by 46% of the carers and for vegetables by 60% of the carers), whilst most carers reported avoiding consuming full-fat dairy products, sugary foods and fried foods. The concept of a healthy diet; typical dietary habits of clients; role in food acquisition; and training in nutrition emerged as themes from the interviews. Carers discussed various topics including the importance of a balanced diet, cooking fresh foods and control of food portion sizes for clients relative to the care philosophy of a client-centred approach, which encapsulates client autonomy. Gaps in knowledge around specific nutrients, making healthy choices and cooking skills remain. Carers have an influence on clients' dietary choices; they are able to provide healthy meals and share good dietary habits with clients. Further training in nutrition is recommended for impact on clients' health.

Evaluating augmented reality for 'real life' teaching of food portion concepts

BACKGROUND

Estimation of food portions is a vital skill for dietitians, which is developed during formal nutrition training. Skill development is often accomplished by training with food portion estimation tools. These tools can vary in design but evaluations often reveal them to be limited in their effectiveness and generally impractical for everyday use. The aim of this study was to develop and evaluate an augmented reality (AR) tool for the estimation food portions.

METHODS

An online, quasi-experimental, randomised pre-test post-test study was conducted to evaluate the effectiveness of three food portion tools with nutrition students. These tools consisted of an online, AR, and an infographic tool (control). Students tested 10 different food images and were asked to estimate food portion sizes with and without assistance of a portion tool to determine absolute error, relative error, and overall improvement in estimation.

RESULTS

A total of 33 participants enrolled in the study with 26 (72.0%) completing the study. The mean absolute error was lowest in the online group (53.0%), followed by AR (59.5%) and control (64.0%). Relative error scores revealed higher accuracy for the AR group (45.5%) followed by online (43.5%), and control group (29.0%). Overall improvement in estimation was highest in the AR group (+12.2%) followed by the online (+11.6%) tool with a decrease seen for the infographic (-1.7%) tool.

CONCLUSIONS

The use of technology, notably AR technology, may provide some advantage when training nutrition students in food portion estimation, although further investigation is advised.

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.

Bone, fat, and muscle interactions in health and disease

Energy metabolism is a point of integration among the various organs and tissues of the human body, not only in terms of consumption of energy substrates but also because it concentrates a wide interconnected network controlled by endocrine factors. Thus, not only do tissues consume substrates, but they also participate in modulating energy metabolism. Soft mesenchymal tissues, in particular, play a key role in this process. The recognition that high energy consumption is involved in bone remodeling has been accompanied by evidence showing that osteoblasts and osteocytes produce factors that influence, for example, insulin sensitivity and appetite. Additionally, there are significant interactions between muscle, adipose, and bone tissues to control mutual tissue trophism. Not by chance, trophic and functional changes in these tissues go hand in hand from the beginning of an individual's development until aging. Likewise, metabolic and nutritional diseases deeply affect the musculoskeletal system and adipose tissue. The present narrative review highlights the importance of the interaction of the mesenchymal tissues for bone development and maintenance and the impact on bone from diseases marked by functional and trophic disorders of adipose and muscle tissues.

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.

Formative evaluation of a portion control and calorie reduction campaign: Insights from focus groups with target audience

Healthy eating campaigns can increase awareness of healthful foods and eating patterns and prompt behavior change. Portion control can be a useful strategy in weight management efforts, and new, innovative campaigns can help invigorate messages related to portion control and weight management. This qualitative study presents results of formative testing of portion control and calorie reduction messages and infographics for a proposed campaign. We conducted 17 focus groups with 113 adults ages 18-65 years in 3 US cities. We conducted separate focus groups by weight status (overweight/healthy weight) and gender (male/female) and analyzed coded data and categorized emerging themes. Participants, especially those with healthy weights, gravitated toward specific, and achievable messages to encourage portion control and calorie reduction. Men with overweight and women with healthy weights preferred messages that had a positive, supportive tone. Participants favored messages that addressed overeating and allowed for autonomy. In particular, women and those with healthy weights preferred messages that encouraged calorie budgeting. Many participants, in particular men, provided positive feedback on messages encouraging a "fresh start" on Mondays. Additionally, participants preferred messages that were colorful, informative, realistic, attractive, and relatable. With regard to message dissemination, participants suggested that messages and infographics be positioned in high-traffic areas and men generally suggested places where food decisions are made. Moreover, participants suggested message dissemination through trusted health professionals and credible research organizations. Health organizations planning a portion control or calorie reduction campaign should consider these factors early in the development process to help ensure acceptance and success.

Perceptions of Weight Loss in Older Adults Following a 6-Month Weight Loss Program: A Qualitative Research Study

BACKGROUND

Obesity in older adults contributes to increasing comorbidities and decreased quality of life. There is limited research that includes older adults' perspectives on weight loss.

OBJECTIVE

The purpose of this qualitative study was to gain a better understanding of older adults' perceptions and experiences related to weight loss immediately after a 6-month weight loss intervention.

DESIGN

A qualitative research design using semi-structured interviews conducted as part of a larger research study exploring weight loss and/or aerobic exercise on muscle inflammation.

PARTICIPANTS/SETTING

A sample of community-based older adults (n = 11) in Southwestern Ohio were recruited from September 2018 through August 2019 after completion of a 6-month weight loss intervention. Eligible participants were older than 58 years, with a body mass index (calculated as kg/m²) >27, and sedentary with no cognitive deficits. Exclusions included cancer, heart disease, diabetes, and tobacco use.

ANALYSIS

Interviews were recorded, transcribed verbatim, and analyzed using thematic analysis. Descriptive statistics were used for demographic data.

RESULTS

Three emergent themes included barriers and challenges to weight loss, which included caregiving roles, challenges with increasing protein intake, and ambivalence to change; personal strategies for success (eg, portion control and meal flexibility); and external strategies for success (eg, visual graphs as feedback measures, alternate measures of success, and social support).

CONCLUSIONS

The results of this qualitative study provide insight into older adults' experiences with weight loss, which may be considered when designing weight management interventions. However, more research is needed to examine strategies to address the challenges identified by participants in this research study. Future qualitative research should also focus on weight loss perspectives of older adults in other racial and ethnic groups.

The Effect of Meal Replacement on Weight Loss According to Calorie-Restriction Type and Proportion of Energy Intake: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Portion control is a useful component of weight reduction interventions and meal replacement (MR) plans represent a promising strategy for portion control. Research performed with pooled data on the effect of MR plans according to various characteristics of MR interventions remains scarce.

OBJECTIVE

Our aim was to assess the effects of MR-based diets compared with food-based diets on weight loss, according to calorie-restriction types and energy intake proportions from MR.

METHODS

Electronic databases (Cochrane Central Register of Controlled Trials, PubMed, Embase, and Research Information Sharing Service) were searched for randomized controlled trials on weight loss results of MR-based calorie-restricted diets compared with food-based calorie-restricted diets from January 2000 to May 2020. Standardized mean differences (Hedges' g) from all study outcomes were calculated using a random-effects model. Heterogeneity was quantified by Q test and I². Publication bias was assessed using a funnel plot and a trim and fill method. Both interventions (MR and control) were separated into very-low-energy diets and low-energy diets (LEDs). A meta-analysis of variance was conducted by dividing patient-related factors and treatment-related factors into subgroups. In multivariable meta-regressions, background variables were selected first, after which main independent variables were included.

RESULTS

Twenty-two studies involving 24 interventions and 1,982 patients who were overweight or obese were included. The effect size in which MR-based LED was compared with food-based LED for weight loss was small, favoring MR (Hedges' g = 0.261; 95% CI 0.156 to 0.365; I² = 21.9; 95% CI 0.0 to 53.6). Diets including ≥60% of total daily energy intake from MR had a medium effect size favoring MR with regard to weight loss among the groups (Hedges' g = 0.545; 95% CI 0.260 to 0.830; I² = 42.7; 95% CI 0.0 to 80.8).

CONCLUSIONS

The effect of MR-based LED on weight loss was superior to the effect of food-based LED, and receiving ≥60% of total daily energy intake from MR had the greatest effect on weight loss.

Identifying behavioral types of dietary lapse from a mobile weight loss program: Preliminary investigation from a secondary data analysis

Success in behavioral weight loss (BWL) programs depends on adherence to the recommended diet to reduce caloric intake. Dietary lapses (i.e., deviations from the BWL diet) occur frequently and can adversely affect weight loss outcomes. Research indicates that lapse behavior is heterogenous; there are many eating behaviors that could constitute a dietary lapse, but they are rarely studied as distinct contributors to weight outcomes. This secondary analysis aims to evaluate six behavioral lapse types during a 10-week mobile BWL program (eating a large portion, eating when not intended, eating an off-plan food, planned lapse, being unaware of caloric content, and endorsing multiple types of lapse). Associations between weekly behavioral lapse type frequency and weekly weight loss were investigated, and predictive contextual characteristics (psychological, behavioral, and environmental triggers for lapse) and individual difference (e.g., age, gender) factors were examined across lapse types. Participants (N = 121) with overweight/obesity (M_BMI = 34.51; 84.3% female; 69.4% White) used a mobile BWL program for 10 weeks, self-weighed weekly using Bluetooth scales, completed daily ecological momentary assessment of lapse behavior and contextual characteristics, and completed a baseline demographics questionnaire. Linear mixed models revealed significant negative associations between unplanned lapses and percent weight loss. Unplanned lapses from eating a large portion, eating when not intended, and having multiple "types" were significantly negatively associated with weekly percent weight loss. A lasso regression showed that behavioral lapse types share many similar stable factors, with other factors being unique to specific lapse types. Results add to the prior literature on lapses and weight loss in BWL and provide preliminary evidence that behavioral lapse types could aid in understanding adherence behavior and developing precision medicine tools to improve dietary adherence.

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.

Alternative diets among adolescents: facts or fads?

PURPOSE OF REVIEW

With rising rates of chronic noninfectious diseases across the United States thought to be associated with the average American diet, many have adopted alternative diets. Most of these diets promise weight reduction via adherence to strict dietary guidelines, often removing certain types of food. With access to a plethora of information online, it is easy for adolescents to become confused when making dietary decisions. Although these diets promise benefits, it is important to understand common shortcomings and how to overcome them for safe implementation among adolescents.

RECENT FINDINGS

This review discusses the theory, implementation, and risks associated with intermittent fasting as well as vegetarian, vegan, ketogenic, Atkins, Paleolithic, and Mediterranean diets. These considerations are further modified for pediatric populations with a focus on the social influences on dieting.

SUMMARY

Although these diets may be promising, successful adherence to them requires addressing possible shortcomings associated with a certain diet. Pediatricians should be aware of how these dietary strategies may be properly implemented in order to prevent any harm to the patient. Empowering the patient and their families through informational resources is recommended. Pediatricians should also discuss motivations underlying their patient's dietary changes in order to determine whether these motivations are healthy.

Unpalatable food for thought: Let marketing research guide effective public obesity interventions

The prevalence of obesity is growing unabatedly despite the considerable efforts directed at the problem. Although abundant research has contributed to our understanding of the multifactorial causes of obesity, there is less attention to research that is relevant for guiding social marketers, public health professionals and policymakers in delivering public health interventions for countering and/or preventing the problem of obesity. This review offers six points for identifying and developing research relevant for guiding community-wide obesity interventions based on the idea that an applied marketing research perspective offers a better model for identifying effective interventions than more theoretical academic research. Specifically, the research guiding public health and social marketing interventions needs to (1) provide information on ultimate outcomes (weight, health and unintended consequences) more than intermediate outcomes (beliefs, attitudes and behaviour), (2) report on observations collected over the longer term, (3) use natural settings (even at a cost of internal validity), (4) endeavour to overcome observer-effects, (5) report effect sizes (rather than statistical significance) and (6) use moderator analyses to capture variation in how a population responds to interventions.

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.

Development and validation testing of a weight management nutrition knowledge questionnaire for adults

Background/Objectives

Because no validated tool exists to assess nutrition knowledge regarding weight management we developed and tested the Weight Management Nutrition Knowledge Questionnaire (WMNKQ).

Subjects/Methods

The questionnaire assesses nutrition knowledge in these categories: energy density of food, portion size/serving size, alcohol and sugar sweetened beverages, how food variety affects food intake, and reliable nutrition information sources. In total 60 questions were reviewed by 6 experts for face validity and quantitative analysis was used to assess item difficulty, item discrimination, internal consistency, inter-item-correlation, test-retest reliability, construct validity, criterion validity, and convergent validity.

Results

The final WMNKQ contained 43 items. Experts removed 3 of the original 60 questions and modified 41. Eighteen items did not meet criteria for item difficulty, item discrimination, and/or inter-item correlation; 4 were retained. The WMNKQ met criteria for internal consistency (Cronbach's alpha = 0.88), reliability (test-retest correlation ρ = 0.90, P < 0.0001), construct validity (known groups comparison) - dietitians scored 16% better (p < 0.0001) than information technology workers, and criterion validity (pre- to post-intervention improvement in knowledge scores = 11.2% (95% CI 9.8–12.5, p < 0.0001)). Participants younger than age 55 scored significantly better than those over age 55 (convergent validity).

Conclusions

The WMNKQ measures how well nutrition principles of weight management are understood.

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.

Modeling Dynamic Food Choice Processes to Understand Dietary Intervention Effects

Background

Meal construction is largely governed by nonconscious and habit-based processes that can be represented as a collection of in dividual, micro-level food choices that eventually give rise to a final plate. Despite this, dietary behavior intervention research rarely captures these micro-level food choice processes, instead measuring outcomes at aggregated levels. This is due in part to a dearth of analytic techniques to model these dynamic time-series events.

Purpose

The current article addresses this limitation by applying a generalization of the relational event framework to model micro-level food choice behavior following an educational intervention.

Method

Relational event modeling was used to model the food choices that 221 mothers made for their child following receipt of an information-based intervention. Participants were randomized to receive either (a) control information; (b) childhood obesity risk information; (c) childhood obesity risk information plus a personalized family history-based risk estimate for their child. Participants then made food choices for their child in a virtual reality-based food buffet simulation.

Results

Micro-level aspects of the built environment, such as the ordering of each food in the buffet, were influential. Other dynamic processes such as choice inertia also influenced food selection. Among participants receiving the strongest intervention condition, choice inertia decreased and the overall rate of food selection increased.

Conclusions

Modeling food selection processes can elucidate the points at which interventions exert their influence. Researchers can leverage these findings to gain insight into nonconscious and uncontrollable aspects of food selection that influence dietary outcomes, which can ultimately improve the design of dietary interventions.

Influence of the nutrition and health information presented on food labels on portion size consumed: a systematic review

Context

In recent decades, portion sizes have increased significantly. Although previous research indicates that food labels impact on product choice and healthiness perception, their impact on portion sizes consumed is less clear.

Objective

This systematic review examined whether food label information influenced portion size consumption.

Data sources

A search of 7 major electronic databases for studies published from 1980 to April 2016 was conducted.

Data extraction

Two reviewers independently screened 11 128 abstracts. Data were extracted from 32 articles (comprising 36 studies).

Results

Based on the test food used, the overall effects were found to be: no effect, a positive effect, or a negative effect. Labels displaying energy content (n = 15 studies, 17 effects) and fat content information (n = 13 studies, 14 effects) were evaluated most commonly, with exercise equivalent labels evaluated least (n = 2 studies, 2 effects).

Conclusions

Nutrition and health information presented on food labels has varying impacts on portion sizes consumed, from increased to decreased intake. Recommendations for future research include evaluating more recent food label types and achieving more consistent reporting standards.

Functional Foods and Bioactive Compounds: A Review of Its Possible Role on Weight Management and Obesity's Metabolic Consequences

Background: Weight management and obesity prevention is a basic aim of health organizations in order to decrease the prevalence of various metabolic disorders. The aim of the present review article was the evaluation of the possible role of functional foods and their bioactive compounds as alternative way to promote weight management and prevent obesity and its metabolic consequences. Methods: Approximately 100 articles were selected from Scopus, PubMed, Google Scholar, and Science Direct, by using relative key words, and based mainly on recent animal, clinical or epidemiological studies. Results: The literature review highlighted the possible effect of specific functional foods such as coffee, green tea, berries, nuts, olive oil, pomegranate, avocado, and ginger. Specific bioactive compounds of those foods—such as caffeine, catechins, gallic acid, anthocyanins, ascorbic acid, polyphenols, oleuropein, capsaicin, and quercetin—may contribute to weight management, obesity prevention, and obesity’s metabolic consequences. The possible mechanisms include effect on satiety, lipid absorption, fatty acids beta oxidation, stimulation of thermogenesis, etc. Conclusions: Functional foods, as part of a balanced diet, could be useful in the direction of weight management and decrease of obesity’s’ metabolic consequences. However, the scientific evidence is unclear and in most cases controversial and more clinical and epidemiological studies are needed in order to further investigate the mechanisms of their possible effect.

A review of evidence supporting current strategies, challenges, and opportunities to reduce portion sizes

Although there is considerable evidence for the portion-size effect and its potential impact on health, much of this has not been successfully applied to help consumers reduce portion sizes. The objective of this review is to provide an update on the strength of evidence supporting strategies with potential to reduce portion sizes across individuals and eating contexts. Three levels of action are considered: food-level strategies (targeting commercial snack and meal portion sizes, packaging, food labels, tableware, and food sensory properties), individual-level strategies (targeting eating rate and bite size, portion norms, plate-cleaning tendencies, and cognitive processes), and population approaches (targeting the physical, social, and economic environment and health policy). Food- and individual-level strategies are associated with small to moderate effects; however, in isolation, none seem to have sufficient impact on food intake to reverse the portion-size effect and its consequences. Wider changes to the portion-size environment will be necessary to support individual- and food-level strategies leading to portion control.

Different and Unequal: A Qualitative Evaluation of Salient Factors Influencing Energy Intake in Adults with Overweight and Obesity

Environmental factors such as food availability and variety can function as cues for overeating in individuals susceptible to overweight or obesity, but relatively little is known about other types of environmental factors that may also be important. This qualitative study compared and contrasted categories of internal and external cues through focus groups and key informant interviews with 24 adults (26 to 77 years old) in the United States who had a body mass index within the healthy range (21.6 ± 2.5 kg/m²) or had overweight or obesity (29.1 ± 3.6 kg/m²). Five domains of external factors influencing food intake were identified: (a) Environmental cues including food availability and variety; (b) normative expectations for dietary intake; (c) food palatability; (d) overt social pressures to overeat; and (e) perceived social expectations around eating. All external domains were noted by participants with overweight or obesity to be challenging, and solutions to avoid overeating were lacking; however, overt social pressures and perceived social expectations appeared to be especially problematic. By explicitly defining different domains of external factors that challenge healthy weight regulation, this study identifies specific targets to address in interventions for healthy weight management.

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.

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.

Facilitators and barriers to a dietitian-implemented blended care weight-loss intervention (SMARTsize): a qualitative study

BACKGROUND

Dietitians play an important role in the intervention and prevention of being overweight and obesity. More and more blended care interventions are being implemented. The present study aimed to evaluate the delivery by Dutch dietitians of a multicomponent, evidence-based weight-loss programme (SMARTsize), including counselling for relapse prevention. The aim of this qualitative study was to identify facilitators and barriers to the delivery of SMARTsize.

METHODS

Nine semi-structured interviews were conducted with 10 dietitians who participated in a larger implementation study. Each interview was recorded and transcribed verbatim. Determinants of theory of implementation, including characteristics of the user, the innovation, organisational context and setting, and innovation strategy guided interviews and analysis. Data were coded and analysed using the framework approach.

RESULTS

According to dietitians, the SMARTsize intervention had a positive influence on patients. The main implementation facilitators were the availability of implementation materials, such as a manual, training in relapse prevention and social support from other dietitians. The main barriers to implementation were organisation and financial reimbursement of cooking classes, the belief that patients need more individual counselling in the starting phase, and the unsuitability for people with low levels of health literacy.

CONCLUSIONS

Most dietitians considered that implementation of the SMARTsize intervention consisting of e-health, written information and cooking classes and face-to-face counselling is challenging but feasible. Further development of the SMARTsize intervention and implementation tools is needed to lower experienced barriers. It is also recommended that a version of the intervention to be developed that is suitable for patients with lower levels of health literacy.

Potential moderators of the portion size effect

AIM

The robust effect of portion size on intake has led to growing interest in why individuals consume more food when served larger portions. A number of explanations have been proposed, and this review aims to provide insight into potential underlying factors by summarizing recent studies testing moderators of the portion size effect.

SUMMARY OF FINDINGS

Provision of portion size information, such as through labeling or training in portion control, failed to attenuate food intake in response to increasing meal size. This indicates that a lack of knowledge about appropriate portions may not be sufficient to explain the portion size effect. In contrast, there is evidence for a role of decision making in the response to large portions, with value being one consideration of importance. The portion size effect may be more closely related to the inherent value of food than monetary value, since provision of the opportunity to take away uneaten food after a meal, which can reduce food waste, attenuated the portion size effect but variations in pricing did not. A number of studies also support an influence of orosensory processing on the portion size effect; large portions have been shown to relate to increased bite size and faster eating rate. Reduced oral processing time when consuming large portions could contribute to the effect by delaying sensory-specific satiety. Findings from a recent study supported this by demonstrating that sensory-specific satiety did not differ between larger and smaller portions despite substantial differences in intake.

CONCLUSIONS

A number of moderators of the portion size effect have been identified, including factors related to the environment, the food, and the individual. It is likely that multiple variables contribute to the response to large portions. Future research should aim to determine the relative contribution of explanatory variables across different contexts and individuals.

Position paper on the need for portion-size education and a standardised unit of measurement

Large portion sizes contribute to weight gain in western societies. Portion-size interventions, aids and education can be effective in helping prevent weight gain, but consumers are unsure what appropriate portions are and express confusion about existing guidelines. A lack of clarity about suggested serving size recommendations is a major barrier to food portion-size control. Therefore, standardised measurement units and unambiguous terminologies are required. This position paper summarises the evidence regarding the impact and importance of portion-size education and estimation, and outlines strategies for improving consumer understanding and application of this through the development of an international food measurement system and a range of appropriate portion control tools. In this position paper, the authors call for the standardisation of food volume measurement terminologies, units, implementation recommendations, as well as consumer education. The target audience for this paper includes nutrition and behavioural researchers, policy makers, and stakeholders who potentially influence and implement changes in national food measurement systems, which in turn impact on consumer choice.

A Process Evaluation of a Multi-Component Intervention in Dutch Dietetic Treatment to Improve Portion Control Behavior and Decrease Body Mass Index in Overweight and Obese Patients

The SMARTsize intervention embeds an evidence-based portion control intervention in regular dietetic care. This intervention was evaluated to explore (1) which patients participated, (2) the implementation process, and (3) the outcomes of the intervention. The intervention was evaluated with an observational study design including measures at baseline, and three, six, and nine months after the start of the program. Data concerning the process (participation, dose delivered, dose received, satisfaction) and the outcomes (self-efficacy, intention, portion control strategies, and Body Mass Index (BMI) were collected with forms and questionnaires filled out by dietitians and patients. Descriptive analyses, comparison analyses, and cluster analyses were performed. Patients were mainly obese, moderately to highly educated women of Dutch ethnicity. Use of the intervention components varied from 50% to 100% and satisfaction with the SMARTsize intervention was sufficient to good (grades 7.2⁻8.0). Statistically significant (p < 0.001) improvements were observed for self-efficacy (+0.5), portion control strategies (+0.7), and BMI (-2.2 kg/m²), with no significant differences between patients with or without counselling. Three clusters of patients with different levels of success were identified. To conclude, implementing an evidence-based portion control intervention in real-life dietetic practice is feasible and likely to result in weight loss.

Examining the Accuracy and Use of Portion Size Estimation Aids in Parents of Children With Obesity: A Randomized Controlled Trial

OBJECTIVE

To determine parents' (1) accuracy in using portion size estimation aids (PSEAs) to estimate portion sizes and (2) use of PSEAs at home.

METHODS

Parents (n = 37) of children in a pediatric weight management clinic were recruited, enrolled in a parallel-design, randomized, controlled trial, and assigned to receive a 2-dimensional (2D) or 3D PSEA. Percent absolute estimation accuracy was examined across groups and food types. Survey responses were organized according to frequencies and percentages were calculated.

RESULTS

Main effects of group, food type, and group × food type interaction were significant (all P < .05). The 2D PSEAs yielded more accurate estimates of portion sizes for amorphous foods. Overall, parents' estimation accuracy was poor. Participants were satisfied and found the PSEAs to be useful.

CONCLUSIONS AND IMPLICATIONS

The 2D PSEAs led to greater accuracy in estimating portions of amorphous foods. Parents showed poor accuracy in estimating portion sizes. This study highlights the role of dietitians and nutrition educators in enhancing portion estimation accuracy.

Portion Control Eating-a Determinant of Bariatric Outcomes

INTRODUCTION

Bariatric surgery leads to significant weight loss but the results vary. Application of dietary principles like portion-controlled eating leads to greater weight loss and fewer complications.

AIMS

To evaluate the improvement in weight loss outcomes by incorporating portion-controlled eating behavior in postbariatric patients.

METHODS

All patients who underwent bariatric surgery from January 2012 to December 2013 were included in the study. Portion-controlled eating behavior was incorporated in the post-bariatric nutritional protocol. Their demographic, preoperative, and postoperative data were prospectively maintained on Microsoft Office Excel and analyzed statistically.

RESULTS

Three hundred and seventy-two (89.6%) underwent laparoscopic sleeve gastrectomy (LSG), while 43 (10.4%) underwent laparoscopic Roux-en-Y gastric bypass (RYGB). In the LSG group, lowest (nadir) BMI was 28.99 ± 5.6 kg/m² and % Excess weight loss (EWL) was 87.3 ± 27.2%, achieved between 1 and 2 years. In the RYGB group, lowest (nadir) BMI was 27.5 ± 12.09 kg/m and % EWL was 94.32 ± 33.12%. Surgical failure (less than 50% EWL) were 10 (3.27%) in the LSG group and 1 (3%) in the RYGB group. There were no leaks reported in our study.

CONCLUSION

Our study highlights the importance of postoperative nutritional interventions like portion-controlled eating for successful bariatric outcome.

Doggy bags and downsizing: Packaging uneaten food to go after a meal attenuates the portion size effect in women

Serving larger portions leads to increased food and energy intake, but little is known about strategies to moderate this response. This study tested how the effect of portion size on meal intake was influenced by providing the option to take away uneaten food in a "doggy bag" (to-go container). Women were randomly assigned to one of two subject groups: a To-Go Group (n = 27) that was informed before each meal that their leftover food would be packaged to take away after the meal, and a Control Group (n = 26) that was not given this option. In a crossover design, subjects came to the lab once a week for four weeks to eat a dinner composed of five foods. Across meals, the portion size of all foods was varied (100%, 125%, 150%, and 175% of baseline). Results showed that the portion size effect, defined as the trajectory of intake across the weight of food served, differed significantly by subject group (P ≤ 0.025). In the Control Group, increasing the portion size of all foods led to substantial increases in intake (P < 0.0001); for every 100 g added to the baseline portion, women in this group consumed an additional mean (±SEM) of 64 ± 12 g of food and 90 ± 19 kcal, until intake leveled off. In contrast, intake of women in the To-Go Group increased by only 17 ± 12 g and 19 ± 18 kcal for every additional 100 g served; these increases did not differ significantly from zero (P > 0.15). Thus, the effect of portion size on intake was attenuated in the To-Go Group compared to the Control Group. These data indicate that packaging uneaten food after a meal could be an effective strategy to reduce overconsumption from large portions.

Does the cost of a meal influence the portion size effect?

Serving larger portions leads to increased intake, but little is known about how the cost of a meal affects this response. Therefore, we tested whether the amount of money paid for a meal influenced the portion size effect at a lunch served in a controlled restaurant-style setting. In a crossover design, 79 adults (55 women; 24 men) came to the lab once a week for 4 weeks to eat a main dish of pasta with side dishes. Across weeks, the meal was varied in two factors: portion size of the main dish (400 g or 600 g) and cost of the meal (US$8 or $16). At discharge subjects completed questionnaires that assessed behaviors thought to influence the response to portion size and cost. Results showed that the portion size of the main dish had a significant effect on meal intake (P < 0.0001). The weight of food consumed at the meal increased by 18 ± 2% (mean ± SEM 83 ± 11 g) and energy intake increased by 20 ± 2% (133 ± 16 kcal) when the larger portion was served. These effects of portion size did not differ across the two levels of cost (both interactions P > 0.37) nor did meal cost have significant effects on meal intake (both P > 0.24). Subject scores for satiety responsiveness did, however, influence the effect of portion size on food intake (P = 0.0007). Serving larger portions led to increased intake in subjects with lower satiety responsiveness scores (P < 0.0001), but did not affect intake in those with higher scores. In summary, the effect of portion size on intake in a restaurant-style setting was not influenced by meal cost but was attenuated in individuals higher in satiety responsiveness.

Comparing the portion size effect in women with and without extended training in portion control: A follow-up to the Portion-Control Strategies Trial

Following a 1-year randomized controlled trial that tested how weight loss was influenced by different targeted strategies for managing food portions, we evaluated whether the effect of portion size on intake in a controlled setting was attenuated in trained participants compared to untrained controls. Subjects were 3 groups of women: 39 participants with overweight and obesity from the Portion-Control Strategies Trial, 34 controls with overweight and obesity, and 29 controls with normal weight. In a crossover design, on 4 different occasions subjects were served a meal consisting of 7 foods that differed in energy density (ED). Across the meals, all foods were varied in portion size (100%, 125%, 150%, or 175% of baseline). The results showed that serving larger portions increased the weight and energy of food consumed at the meal (P < .0001), and this effect did not differ across groups. Increasing portions by 75% increased food intake by a mean (±SEM) of 111 ± 10 g (27%) and increased energy intake by 126 ± 14 kcal (25%). Across all meals, however, trained participants had lower energy intake (506 ± 15 vs. 601 ± 12 kcal, P = .006) and lower meal ED (1.09 ± 0.02 vs. 1.27 ± 0.02 kcal/g; P = .003) than controls, whose intake did not differ by weight status. The lower energy intake of trained participants was attributable to consuming meals with a greater proportion of lower-ED foods than controls. These results further demonstrate the robust nature of the portion size effect and reinforce that reducing meal ED is an effective way to moderate energy intake in the presence of large portions.

Portion size and later food intake: evidence on the "normalizing" effect of reducing food portion sizes

Background

Historical increases in the size of commercially available food products have been linked to the emergence of a worldwide obesity crisis. Although the acute effect that portion size has on food intake is well established, the effect that exposure to smaller portion sizes has on future portion size selection has not been examined.

Objective

We tested whether reducing a food portion size "renormalizes" perceptions of what constitutes a normal amount of that food to eat and results in people selecting and consuming smaller portions of that food in the future.

Design

Across 3 experiments, participants were served a larger or smaller portion of food. In experiments 1 and 2, participants selected and consumed a portion of that food 24 h later. In experiment 3, participants reported on their preferred ideal portion size of that food after 1 wk.

Results

The consumption of a smaller, as opposed to a larger, portion size of a food resulted in participants believing a "normal"-sized portion was smaller (experiments 1-3, P ≤ 0.001), consuming less of that food 1 d later (experiments 1-2, P ≤ 0.003), and displaying a tendency toward choosing a smaller ideal portion of that food 1 wk later (experiment 3, P = 0.07), although the latter finding was not significant.

Conclusion

Because consumer preferences appear to be driven by environmental influences, reducing food portion sizes may recalibrate perceptions of what constitutes a "normal" amount of food to eat and, in doing so, decrease how much consumers choose to eat. This trial was registered at www.clinicaltrials.gov as NCT03241576.

Association between excess weight and beverage portion size consumed in Brazil

OBJECTIVE To describe the beverage portion size consumed and to evaluate their association with excess weight in Brazil. METHODS We used data from the National Dietary Survey, which included individuals with two days of food record aged over 20 years (n = 24,527 individuals). The beverages were categorized into six groups: soft drink, 100% fruit juice, fruit drink, alcoholic beverage, milk, and coffee or tea. We estimated the average portion consumed for each group and we evaluated, using linear regression, the association between portion size per group and the variables of age, sex, income, and nutritional status. We tested the association between portion size and excess weight using Poisson regression, adjusted for age, sex, income, and total energy intake. RESULTS The most frequently consumed beverages in Brazil were coffee and tea, followed by 100% fruit juices, soft drinks, and milk. Alcoholic beverages presented the highest average in the portion size consumed, followed by soft drinks, 100% fruit juice, fruit drink, and milk. Portion size showed positive association with excess weight only in the soft drink (PR = 1.19, 95%CI 1.10-1.27) and alcoholic beverage groups (PR = 1.20, 95%CI, 1.11-1.29), regardless of age, sex, income, and total energy intake. CONCLUSIONS Alcoholic beverages and soft drinks presented the highest averages in portion size and positive association with excess weight. Public health interventions should address the issue of portion sizes offered to consumers by discouraging the consumption of large portions, especially sweetened and low nutritional beverages.

Research into food portion size: methodological aspects and applications

Portion sizes for certain foods have been increasing dramatically in recent years alongside obesity rates, concurring with the phenomenon of the portion size effect (more is consumed when more is offered). Portion size may be defined based on different purposes such as for dietary assessment, or therapeutic advice or food labelling, resulting in a variety of measurement methods and specifications. This situation has resulted in disagreements on establishing portion size recommendations by manufacturers, food distributors, restaurants, health professionals and policy makers, contributing to confusion amongst consumers on the amounts of food to be consumed, and potentially increasing the likelihood of overeating and other obesity-related behaviours. Such variability is also reflected in the research field making comparison across studies on portion size difficult. The aim of this review is to provide an overview of definitions and methods used in research to evaluate portion-size related outcomes, including methods to estimate amounts consumed by individuals as part of dietary assessment; methods to analyse cognitive mechanisms related to portion size behaviour; and methods to evaluate the impact of portion size manipulations as well as individual plus environmental factors on portion size behaviour. Special attention has been paid to behavioural studies exploring portion size cognitive processes given the lack of previous methodological reviews in this area. This information may help researchers, clinicians and other stakeholders to establish clearer definitions of portion size in their respective areas of work and to standardise methods to analyse portion size effects.

Support needs of patients with obesity in primary care: a practice-list survey

BACKGROUND

UK guidelines recommend that patients with obesity in primary care receive opportunistic weight loss advice from health care professionals, but there is a lack of research into the characteristics and existing weight management practices of these patients. The aim of this study was to characterise primary care patients with obesity in England, to inform the screening, support, and referral options appropriate to this group.

METHODS

We surveyed 1309 patients registered at 15 GP practices in North East England, aged ≥18 years and with objectively recorded obesity (BMI ≥ 30 kg/m2). Study participants reported their weight history, health status, past and current weight loss activities, motivating factors, weight loss strategies used, professional support received, and perceived barriers to weight loss.

RESULTS

62% of participants were actively trying to lose weight, and a further 15% had attempted and discontinued weight loss in the last 12 months. Only 20% of the sample had sought GP support for weight loss in the last 12 months; instead, most efforts to lose weight were self-guided and did not use evidence-based strategies. Those who sought GP weight loss support were likely to use it and find it motivating. Participants had attempted weight loss on multiple previous occasions and overall felt less confident and successful at maintaining weight loss than losing it. Participants at greatest clinical risk (higher BMI and more health conditions) reported particularly low confidence and multiple barriers to weight loss, but were nevertheless highly motivated to lose weight and keep it off.

CONCLUSIONS

We identified the need for informational, structural, and weight loss maintenance-specific support for GP patients with objectively-recorded obesity. Study participants were motivated to lose weight and keep it off, but lacked the confidence and understanding of effective strategies required to do this. GP weight loss support was acceptable and useful but underutilised, indicating that screening and brief referral interventions to structured programmes may augment patients' current weight management activities and meet key support needs whilst optimising limited primary care resources.

Dietary Management of Obesity: Cornerstones of Healthy Eating Patterns

Several dietary patterns, both macronutrient and food based, can lead to weight loss. A key strategy for weight management that can be applied across dietary patterns is to reduce energy density. Clinical trials show that reducing energy density is effective for weight loss and weight loss maintenance. A variety of practical strategies and tools can help facilitate successful weight management by reducing energy density, providing portion control, and improving diet quality. The flexibility of energy density gives patients options to tailor and personalize their dietary pattern to reduce energy intake for sustainable weight loss.

Serotonin-transporter promoter polymorphism modulates the ability to control food intake: Effect on total weight loss

SCOPE

The biggest challenge for losing weight is the ability to control the amount of food eaten; the tendency to overeat is called disinhibition. Our aims were to determine whether (a) the SLC6A4-promoter variant (5-HTTLPR) relates to disinhibition; (b) this association could affect total weight-loss during a behavioral/dietary treatment for obesity.

METHODS AND RESULTS

A total of 2961 subjects attended voluntarily five weight-loss clinics; a subsample (n = 624) was recruited for SLC6A4 genotyping. Total weight-loss, emotional-eating-score and disinhibition-score were examined. We observed that: (a) the reduced ability to control food intake (disinhibition) is implicated in the impairment to lose weight; (b) SLC6A4-promoter variant is implicated in disinhibition. S carriers (low-expressing) of the SLC6A4-promoter variant had a lower inhibition capacity and showed more failure (1.6 times) to control the amount of food eaten than LL (p < 0.05); other factors such as eating while bored, overeating after work at night, or craving for specific foods were associated to the SLC6A4 genotype (p < 0.05); (c) The combination of disinhibition (high disinhibition) and genetics (S carrier) had a higher impact on total weight loss than each factor separately.

CONCLUSIONS

SLC6A4-promoter variant is associated with the ability to control food intake and interacts with emotional eating to modulate total weight loss.