What determines real-world meal size? Evidence for pre-meal planning

Self-compassion and reasons individuals stop eating: An exploratory investigation

BACKGROUND

Self-compassion is a prevalent factor that has been explored in eating behaviour and weight loss literature. The present study explored the potential relationship between self-compassion and reasons individuals stop eating.

METHOD

Two hundred and eighty-three participants were recruited from social media platforms and a research participation scheme at a university in the West Midlands, UK, and completed questionnaires on self-compassion and reasons individuals stop eating.

RESULTS

The findings suggested that self-compassion was negatively associated with decreased food appeal, self-consciousness, and decreased food priority, whilst being positively associated with physical satisfaction.

CONCLUSION

Self-compassion plays a prevalent role in the reasons individuals stop eating, and future research should continue exploring the effect of self-compassion on eating behaviour regulation.

Exploring within-meal variety to promote appeal of home-cooked meals in older adults

Undernutrition is highly prevalent in older adults and poses a major threat to physical and mental wellbeing. To foster healthy eating (and healthy aging), strategies are needed to improve dietary quality of older adults. In this study, the feasibility of increasing food variety in home-cooked meals is explored as strategy to promote meat and vegetable consumption in community dwelling older adults. Adults aged 50 years or older (N = 253) evaluated pictures of traditional Dutch dinner meals with more or less variety in the vegetable or meat component in an online questionnaire. Specifically, four different variety 'levels' were presented: (1) no variety, (2) meat variety, (3) vegetable variety, and (4) variety in both meat and vegetables (mixed). Participants indicated for each meal picture how much they would like the meal, whether it represented an ideal portion size, and whether they would be able and willing to prepare the meal. We expected that with increasing variety, liking and ideal portion size would increase, while ability and willingness to prepare the meals would decrease. Results showed that the meals with meat variety and mixed variety were liked less than meals with vegetable variety or no variety. Participants were all highly willing to prepare the meals, but they were less willing to prepare the meals with meat variety and mixed variety compared to the meals with vegetable variety and no variety. All meals were evaluated as being too large, but the meals with vegetable variety and mixed variety were evaluated as more oversized than the meals without variety and with meat variety. These results suggest that encouraging older adults to include variety in home-cooked meals might be more challenging than anticipated.

Reasons for meal termination, eating frequency, and typical meal context differ between persons with and without a spinal cord injury

Overeating associated with neurogenic obesity after spinal cord injury (SCI) may be related to how persons with SCI experience satiation (processes leading to meal termination), their eating frequency, and the context in which they eat their meals. In an online, cross-sectional study, adults with (n = 688) and without (Controls; n = 420) SCI completed the Reasons Individuals Stop Eating Questionnaire-15 (RISE-Q-15), which measures individual differences in the experience of factors contributing to meal termination on five scales: Physical Satisfaction, Planned Amount, Decreased Food Appeal, Self-Consciousness, and Decreased Priority of Eating. Participants also reported weekly meal and snack frequency and who prepares, serves, and eats dinner with them at a typical dinner meal. Analysis revealed that while Physical Satisfaction, Planned Amount, and Decreased Food Appeal were reported as the most frequent drivers of meal termination in both groups, scores for the RISE-Q-15 scales differed across the groups. Compared to Controls, persons with SCI reported Physical Satisfaction and Planned Amount as drivers of meal termination less frequently, and Decreased Food Appeal and Decreased Priority of Eating more frequently (all p < 0.001). This suggests that persons with SCI rely less on physiological satiation cues for meal termination than Controls and instead rely more on hedonic cues. Compared to Controls, persons with SCI less frequently reported preparing and serving dinner meals and less frequently reported eating alone (all p < 0.001), indicating differences in meal contexts between groups. Individuals with SCI reported consuming fewer meals than Controls but reported a higher overall eating frequency due to increased snacking (p ≤ 0.015). A decrease in the experience of physical fullness, along with a dependence on a communal meal context and frequent snacking, likely contribute to overeating associated with neurogenic obesity after SCI.

The Impact of Modifiable Preoral Factors on Swallowing and Nutritional Outcomes in Healthy Adults: A Scoping Review

PURPOSE

Swallowing has previously been characterized as consisting of four phases; however, it has become apparent that these four phases are not truly discrete and may be influenced by factors occurring prior to bolus entrance into the oral cavity (i.e., preoral factors). Still, the relationship between these factors and swallowing remains poorly understood. The aim of this review was to synthesize and characterize the literature pertaining to the influence of preoral factors on swallowing and nutritional outcomes in healthy individuals.

METHOD

We performed a scoping review, searching the databases of PubMed, CINAHL, Cochrane, and Scopus. Search terms included those related to swallowing, experience of preoral factors, and exclusionary terminology to reduce animal and pediatric literature. Our initial search revealed 5,560 unique articles, of which 153 met our inclusionary criteria and were accepted into the review.

RESULTS

Of the accepted articles, 78% were focused exclusively on nutritional outcomes, 17% were focused on both swallowing and nutritional outcomes, and 5% were focused on solely swallowing outcomes. Of the preoral factors examined, 99% were exteroceptive in nature (17% olfactory, 44% visual, 21% auditory, 7% tactile, 11% other), while 1% were proprioceptive in nature.

CONCLUSIONS

This review supports the influence of preoral factors on swallowing and nutritional outcomes. However, there is a large emphasis on the visual modality and on nutritional outcomes. Nearly none of the literature found in this review directly measured swallowing safety, efficiency, or physiology. Future work will benefit from a larger focus on proprioceptive preoral factors as they relate to swallowing outcomes.

On the measurement and correlates of plate clearing: examining a German version of the Plate Clearing Tendency Scale

PURPOSE

Plate clearing-eating a meal in its entirety-is common and may be a factor contributing to obesity. For the assessment of individual differences in plate clearing tendencies, Robinson et al. (Obesity 23:301-304, 2015) developed the Plate Clearing Tendency Scale (PCTS). However, little is known about the psychometric properties of this scale and its correlates.

METHODS

In the current study, participants (N = 207, 76% female) completed a German translation of the PCTS and other questionnaires online.

RESULTS

A one-factor structure had good model fit and the PCTS had acceptable internal reliability and good test-retest reliability across an average of four and a half weeks. Higher plate clearing tendencies related to more frequent parental encouragement to clear one's plate in childhood and to stronger food waste concerns but were unrelated to sex, body weight, self-control, and eating behaviors. However, higher plate clearing tendencies related to higher body weight in unsuccessful dieters.

CONCLUSION

The current study shows that the PCTS has sound psychometric properties and that plate clearing tendencies appear to be largely driven by food waste concerns and not by automatic eating habits or low eating-related self-control. In dieters, however, high plate clearing tendencies may contribute to low dieting success and hinder weight loss.

LEVEL OF EVIDENCE

No level of evidence, basic science.

People's intended serving behaviour at social vs. non-social meals

The social facilitation of eating refers to people's tendency to eat more food when dining with others than when dining alone. Recent research suggests that social facilitation may be driven by people's tendency to make more food available even before social meals begin, a phenomenon referred to as social "precilitation." In order to uncover the mechanisms underlying social precilitation, it is helpful to first understand whether people consciously and deliberately make more food available for social meals. Three studies (total N = 792) used an online serving paradigm to investigate this question. Participants were asked to imagine dining alone and dining socially, and indicated how much food they would serve themselves in each scenario. Unexpectedly, participants consistently reported intending to serve themselves smaller portions for social meals than for non-social meals (Study 1). This effect emerged even when they were asked about how someone else would behave (Study 2), and when they were informed that there was plenty of food available at the social meal (Study 3). This research highlights a disconnect between people's intended serving behaviour and the actual serving behaviour observed in laboratory studies, and suggests that people may not be aware of how their behaviour is influenced by the social context. Future research should examine why the disconnect between people's intended and actual serving behaviour occurs, whether it is related to the amount of food provided for social meals, and what implications the disconnect has for people's ability to manage their food intake.

The effects of nutrition and health claims on the nutrient composition of single and subsequent meal servings

Nutrition and health claims (NHCs) can help individuals make better food choices. While NHCs have been found to influence consumer perceptions and consumption, there has been less focus on how claims influence the nutritional composition of servings. There has also been little attention paid to longer term or compensatory effects of claims on subsequent food selection. This manuscript details two studies considering these matters. Study 1 (n = 60) was a within-subjects experiment to measure the impact of NHCs on food selection and nutritional composition at single meal servings. Participants served from three fake food buffet meal stations (breakfast, hot meal, snacks) with NHCs present or absent. Study 2 (n = 55) was a within-subjects experiment to examine the impact of NHCs on food selection and nutritional composition at a subsequent meal. Participants served from a fake food buffet breakfast with or without NHCs followed by a lunch without NHCs. In study 1, while results varied for different meals, the presence of claims was found to significantly reduce the amount of energy, fat, saturated fat, sugar, carbohydrates, and sodium, and increase the amount of protein in meals that were served. Results for fibre were mixed. In addition, NHCs increased the quantity of food served in the snacks condition. There was no evidence of claims at breakfast impacting the nutritional composition of subsequent lunch servings in study 2. Despite claims potentially increasing serving quantities, the nutritional composition of chosen servings was more encouraging and claims may help individuals to meet recommended nutritional daily guidelines. These findings have wider implications in terms of government policy, food reformulation, and the continuing debate around the use of nutrient profiling regulations for products carrying claims.

Influence of social-normative information on the modeling of food-related decisions

Social modeling is a powerful influence on people's food intake: When there is a clear and consistent norm, people eat more when eating with someone who eats a lot and eat less when eating with someone who eats only a little. In three studies, the present research examined how clear versus ambiguous social-normative information influences the modeling of food-related decisions. Using a novel online decision-making paradigm, female participants (total N = 1042) were provided with information about how many cookies previous participants had supposedly selected (no information was provided in the control condition), and then decided how many cookies they would choose for a snack. When there was a clear and consistent norm, the typical social modeling effect was observed. When there was a small number of "dissenters" whose responses conflicted with the norm set by the majority, participants' cookie selection still conformed to the behaviour of the majority (Studies 1 and 2). It was only when the behaviour of the previous participants was highly ambiguous that participants behaved as if they had been given no normative information (Study 3). By demonstrating that, except in extreme cases, people use the available information to discern a social norm that influences their behaviour, these findings highlight the power of social norms related to food-related decisions.

Transformation in culinary behaviour during the COVID-19 pandemic: In-depth interviews with food gatekeepers in urban India

COVID-19 and its associated regulatory measures including lockdowns, curfews, and physical distancing norms have significantly affected individual's dietary and culinary behaviours. Although there is ample empirical evidence available on dietary changes within the Indian context, very limited evidence exists about the factors influencing these dietary modifications and changes in culinary behaviours during COVID-19 lockdown. Therefore, the aim of this qualitative study was to explore the views of Indian household food gatekeepers towards meal planning, food purchasing, and meal preparation during the pandemic and its associated lockdowns. A convenience sample of 34 female gatekeepers from the Mumbai metropolis participated in online interviews. Interviews were conducted in English and Hindi (then translated in English), audio-recorded and transcribed verbatim. Underpinned by Template Analysis technique, transcribed data were analysed manually and using the NVivo software program. The interview structure guided the development of themes. The emerging themes included were: Increased household cooking; Involvement of children and male members in food-related activities; Experimentation in the kitchen; Adoption of meal planning skills; Increase in online food shopping; Bulk buying; Shortage of food items; Reduced consumption of outside home food; Increased variety of home-cooked meals; Increase in snacking and overall food intake; Determinants of food choices; and Family meals-a new norm. In the light of these findings, developing family-focussed, web-based nutrition programs to enhance gatekeepers' and their families' food literacy including declarative and procedural nutritional knowledge would be beneficial. The importance of organisational culinary behaviours such as planning meals in advance, shopping with a food list should be promoted to prevent hoarding and subsequently reduce strain on the food supply system. With a surge in domestic cooking, low cost nutritious recipes with the use of local and seasonal produce should be emphasized promoting healthy eating among the gatekeepers and their family members. The inclusion of food studies in the school curriculum will facilitate the development of culinary skills among children and youth. Also, there is a need for further research and surveillance to strengthen understanding of sustainability of healthy culinary behaviours practiced during the pandemic.

Construct validation of the Reasons Individuals Stop Eating Questionnaire (RISE-Q) and the development of the RISE-Q-15

Consumers vary in the explanations they give for meal termination. The Reasons Individuals Stop Eating Questionnaire (RISE-Q) was developed to measure these satiation processes. Individual differences in satiation may be associated with a general capacity to recognise and respond to contextual and interoceptive cues. The aims of the present study were to validate the factor structure of the RISE-Q and to explore its construct validity. In particular, we tested the prediction that a latent variable "Sensitivity to Internal Satiation Cues" is associated with high satiety responsiveness, high scores on the RISE-Q Physical Satisfaction (PS) and Decreased Food Appeal (DFA) scales and a healthy BMI. Participants (n = 216 adults) completed an online survey which included the RISE-Q, Mindful Eating Questionnaire, Multidimensional Assessment of Interoceptive Awareness, Adult Eating Behaviour Questionnaire (AEBQ) and self-reported height and weight. Confirmatory Factor Analysis supported the 5-factor structure of the RISE-Q, but model fit was improved by a new short form (RISE-Q-15) of the questionnaire. Construct validity replicated for most RISE-Q subscales, but not RISE-Q and BMI. Structural Equation Modelling demonstrated that Sensitivity to Internal Satiation Cues was associated with RISE-Q PS but not with the DFA, whereas AEBQ Satiety Responsiveness was associated with DFA, but not with PS. The RISE-Q-15 may be more sensitive to specific meal termination behaviours than pre-existing questionnaires, and due to its low participant burden, it provides a useful tool to explore further multiple processes of satiation in various contexts.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

The Satiation Framework: Exploring processes that contribute to satiation

Satiation has been described as a process that leads to the termination of eating and controls meal size. However, studies have shown that the termination of eating can be influenced by multiple behavioral and biological processes over the course of a meal as well as those related to the context in which the meal is consumed. To expand understanding of how individuals experience satiation during a meal, we recently developed the Reasons Individuals Stop Eating Questionnaire (RISE-Q). The development of the RISE-Q revealed five distinct factors reported to contribute to meal termination: Planned Amount, Self-Consciousness, Decreased Food Appeal, Physical Satisfaction, and Decreased Priority of Eating. Thus, we define satiation as a series of dynamic processes that emerge over the course of a meal to promote meal termination. We suggest that each of the factors identified by the RISE-Q represents a distinct process, and illustrate the contribution of each process to meal termination in the Satiation Framework. Within this framework the prominence of each process as a reason to stop eating likely depends on meal context in addition to individual variability. Therefore, we discuss contexts in which different processes may be salient as determinants of meal termination. Expanding the definition of satiation to include several dynamic processes as illustrated in the Satiation Framework will help to stimulate investigation and understanding of the complex nature of meal termination.

When do children learn how to select a portion size?

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

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

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

Planned morning aerobic exercise in a fasted state increases energy intake in the preceding 24 h

Purpose

We previously observed increased energy intake (EI) at the meal before planned afternoon exercise, but the proximity of the meal to exercise might have reduced the scale of the pre-exercise anticipatory eating. Therefore, this study examined EI in the 24 h before fasted morning exercise.

Methods

Fourteen males, experienced with gym-based aerobic exercise (age 25 ± 5 years, BMI 23.8 ± 2.5 kg/m²), completed counterbalanced exercise (EX) and resting (REST) trials. On day 1, subjects were told the following morning’s activity (EX/REST), before eating ad-libitum laboratory-based breakfast and lunch meals and a home-based afternoon/evening food pack. The following morning, subjects completed 30-min cycling and 30-min running (EX; 3274 ± 278 kJ) or 60-min supine rest (REST; 311 ± 34 kJ) fasted. Appetite was measured periodically, and EI quantified.

Results

Afternoon/evening EI (EX 7371 ± 2176 kJ; REST 6437 ± 2070 kJ; P = 0.017) and total 24-h EI (EX 14,055 ± 3672 kJ; REST 12,718 ± 3379 kJ; P = 0.011) were greater during EX, with no difference between trials at breakfast (P = 0.761) or lunch (P = 0.071). Relative EI (EI minus energy expended through EX/REST) was lower in EX (EX 10,781 ± 3539 kJ; REST 12,407 ± 3385 kJ; P = 0.004).

Conclusion

This study suggests planned fasted aerobic exercise increases EI during the preceding afternoon/evening, precipitating a ~ 10% increase in EI in the preceding 24-h. However, this increase did not fully compensate for energy expended during exercise; meaning exercise induced an acute negative energy balance.

Development and validation of the Reasons Individuals Stop Eating Questionnaire (RISE-Q): A novel tool to characterize satiation

A variety of factors can influence satiation, and individual differences in reasons for meal termination may help to explain variability in food intake and susceptibility to overconsumption. We developed and validated a questionnaire to characterize the Reasons Individuals Stop Eating (RISE-Q). The initial RISE-Q was created by reviewing the published literature and identifying 47 reasons why individuals might stop eating. The RISE-Q asks respondents to rate how often each reason influences why they stop eating at a typical dinner meal by using a seven-point scale. Adults (N = 477, 77% women) from a participant database completed a survey online that included the initial RISE-Q and the satiation-related Satiety Responsiveness and Food Responsiveness scales of the Adult Eating Behavior Questionnaire (AEBQ). Self-reported height and weight were collected to calculate body mass index (BMI). The survey also assessed self-reported typical meal size. After factor analysis, the RISE-Q retained 31 items and identified five distinct scales of reasons for stopping eating: Decreased Food Appeal (mean ± SD: 2.6 ± 0.05, Cronbach's α = 0.89), Physical Satisfaction (5.0 ± 0.04, α = 0.85), Planned Amount (4.4 ± 0.05, α = 0.82), Self-Consciousness (2.4 ± 0.05, α = 0.88), and Decreased Priority of Eating (2.3 ± 0.04, α = 0.69). Thus, the most frequently reported reasons for meal termination were related to Physical Satisfaction and Planned Amount. Each RISE-Q scale was significantly correlated with at least one of the satiation-related AEBQ scales, suggesting that the RISE-Q has construct validity. RISE-Q scales were also correlated with BMI and measures of typical meal size. The RISE-Q provides a novel tool to assess differences across individuals in reported reasons for eating cessation. The RISE-Q can aid in further understanding risk factors for overconsumption and has potential clinical utility in the design of targeted weight-management interventions.

Consumer perception of food variety in the UK: an exploratory mixed-methods analysis

BACKGROUND

'Food variety' is a key term that is frequently used in dietary guidelines around the world. Consuming a variety of foods - be it within a meal, across meals, or as part of the whole diet - is one factor that has been shown to increase food intake. However, little is known about consumer understanding of variety, and this may be a potential barrier to the success of dietary guidelines in today's 'obesogenic' environment. This research sought to explore 1) consumer recognition of different forms of variety, and 2) consumer definitions of variety.

METHODS

In an online study (N = 240), participants were asked to discuss a range of photographs depicting different forms of variety, and to directly define the term 'food variety'. They were unaware of the research aim.

RESULTS

Using a mixed methods approach, directed content analysis of these data showed that individuals referenced multiple forms of variety in the presence of food photographs. However, when asked to define variety, participants tended to only discuss variety in the context of the whole diet.

CONCLUSIONS

These findings emphasise a need to educate consumers about variety to encourage adherence to dietary guidelines and help consumers better manage their own food intake.

Food waste concerns, eating behaviour and body weight

Consumer food waste is now a significant social issue. However, given that the modern day food environment has become characterised by larger portion sizes of more energy-dense foods, personal concerns about wasting food may result in eating behaviours that promote excess energy intake and weight gain. Across 3 studies, we developed a brief (5-item) measure to quantify concerns about food waste and examined the relationships between food waste concerns, eating behaviour and body weight. In Study 1, we showed that our 5-item measure of food waste concerns has acceptable convergent and divergent validity, and test-retest reliability. We also found that concerns about wasting food were predictive of greater behavioural intentions to avoid food waste (e.g. eating leftovers). In Study 2, greater food waste concerns were associated with an increased tendency to plate-clear when eating (self-reported), but not with objectively measured body weight or likelihood of having overweight or obesity. In Study 3, we examined how much food participants consumed when served a large portion size of a lunchtime meal and found that food waste concerns did not directly or indirectly predict how much participants ate. Overall, we found evidence that concerns about food waste are related to self-reported intentions to minimize food waste and plate-clearing tendencies, but no evidence that food waste concerns are related to objectively measured energy intake in the laboratory or body weight.

The Metabolic Concept of Meal Sequence vs. Satiety: Glycemic and Oxidative Responses with Reference to Inflammation Risk, Protective Principles and Mediterranean Diet

With increasing exposure to eating opportunities and postprandial conditions becoming dominant states, acute effects of meals are garnering interest. In this narrative review, meal components, combinations and course sequence were questioned vis-à-vis resultant postprandial responses, including satiety, glycemic, oxidative and inflammatory risks/outcomes vs. protective principles, with reference to the Mediterranean diet. Representative scientific literature was reviewed and explained, and corresponding recommendations discussed and illustrated. Starting meals with foods, courses and/or preloads high in innate/added/incorporated water and/or fibre, followed by protein-based courses, delaying carbohydrates and fatty foods and minimizing highly-processed/sweetened hedonic foods, would increase satiety-per-calorie vs. obesogenic passive overconsumption. Similarly, starting with high-water/fibre dishes, followed by high-protein foods, oils/fats, and delayed/reduced slowly-digested whole/complex carbohydrate sources, optionally closing with simpler carbohydrates/sugars, would reduce glycaemic response. Likewise, starting with foods high in innate/added/incorporated water/fibre/antioxidants, high monounsaturated fatty acid foods/oils, light proteins and whole/complex carbohydrate foods, with foods/oils low in n-6 polyunsaturated fatty acids (PUFA) and n-6:n-3 PUFA ratios, and minimal-to-no red meat and highly/ultra-processed foods/lipids, would reduce oxidative/inflammatory response. Pyramids illustrating representative meal sequences, from most-to-least protective foods, visually communicate similarities between axes, suggesting potential unification for optimal meal sequence, consistent with anti-inflammatory nutrition and Mediterranean diet/meal principles, warranting application and outcome evaluation.

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.

Health, pleasure, and fullness: changing mindset affects brain responses and portion size selection in adults with overweight and obesity

BACKGROUND

Increased portion size is an essential contributor to the current obesity epidemic. The decision of how much to eat before a meal begins (i.e. pre-meal planning), and the attention assigned to this task, plays a vital role in our portion control.

OBJECTIVE

We investigated whether pre-meal planning can be influenced by a shift in mindset in individuals with overweight and obesity in order to influence portion size selection and brain activity.

DESIGN

We investigated the neural underpinnings of pre-meal planning in 36 adults of different weight groups (BMI < 25 kg/m² and BMI ≥ 25 kg/m²) by means of functional magnetic resonance imaging. To examine the important role of attentional focus, participants were instructed to focus their mindset on the health effects of food, expected pleasure, or their intention to stay full until dinnertime, while choosing their portion size for lunch.

RESULTS

We observed that participants of all weight groups reduced their portion size when adopting a health mindset, which was accompanied by enhanced activation of the self-control network (i.e. left prefrontal cortex). Fullness and pleasure mindsets resulted in contrasting reward responses in individuals with overweight and obesity compared to normal-weight individuals. Under the pleasure mindset, persons with overweight and obesity showed heightened activity in parts of the taste cortex (i.e. right frontal operculum), while the fullness mindset caused reduced activation in the ventral striatum, an important component of the reward system. Moreover, participants with overweight and obesity did not modify their behaviour under the pleasure mindset and selected larger portions than the normal-weight group.

CONCLUSIONS

We were able to identify specific brain response patterns as participants made a final choice of a portion size. The results demonstrate that different brain responses and behaviours during pre-meal planning can inform the development of effective strategies for healthy weight management.

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.

Food portion size influences accompanying beverage selection in adults

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

Increased Hunger, Food Cravings, Food Reward, and Portion Size Selection after Sleep Curtailment in Women Without Obesity

This study examined the effects of one night of sleep curtailment on hunger, food cravings, food reward, and portion size selection. Women who reported habitually sleeping 7⁻9 h per night, were aged 18⁻55, were not obese, and had no sleep disorders were recruited. Sleep conditions in this randomized crossover study consisted of a normal night (NN) and a curtailed night (CN) where time in bed was reduced by 33%. Hunger, tiredness, sleep quality, sleepiness, and food cravings were measured. A progressive ratio task using chocolates assessed the food reward. Participants selected portions of various foods that reflected how much they wanted to eat at that time. The sleep duration was measured using a single-channel electroencephalograph. Twenty-four participants completed the study. The total sleep time was shorter during the CN (p < 0.001). Participants reported increased hunger (p = 0.013), tiredness (p < 0.001), sleepiness (p < 0.001), and food cravings (p = 0.002) after the CN. More chocolate was consumed after the CN (p = 0.004). Larger portion sizes selected after the CN resulted in increased energy plated for lunch (p = 0.034). In conclusion, the present study observed increased hunger, food cravings, food reward, and portion sizes of food after a night of modest sleep curtailment. These maladaptive responses could lead to higher energy intake and, ultimately, weight gain.

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.

Plating up appropriate portion sizes for children: a systematic review of parental food and beverage portioning practices

Consumption of larger portion sizes is associated with higher energy intake and weight status in children. As parents play a pivotal role in child feeding, we synthesized literature on 'parental portioning practices' using a mixed methods systematic design to inform future strategies addressing portion sizes served to children. Electronic databases PubMed, EMBASE, SCOPUS, PsycINFO and CINAHL Plus were searched. Two reviewers independently screened 385 abstracts and assessed 71 full-text articles against eligibility criteria: studies assessing portioning of foods or beverages by parent(s) with ≥1 child aged 2-12 years. Narrative synthesis of 14 quantitative studies found that portion sizes parents serve vary substantially and are influenced by amounts parents serve themselves, perceived child hunger and parent and child body size. Thematic synthesis of 14 qualitative studies found that parents serve the portion sizes they learn to be appropriate for their child to be fed. Portioning is influenced by parents' desires for a healthy child with a balanced diet. Future guidance on appropriate portion sizes for children would ideally present recommended portion sizes for first serving, incremental with age. Future research is however needed to assess the adoption and efficacy of providing such guidance to families.

Combating Excessive Eating: A Role for Four Evidence-Based Remedies

OBJECTIVE

The aim of this study is to review the control of energy balance and outline some causes of and remedies for excessive energy intake.

METHODS

A narrative review was conducted.

RESULTS

There is negative feedback control of energy intake and body weight, but, nonetheless, energy intake is only loosely coupled with energy expenditure. Consequently, we are vulnerable to eating in excess of energy requirements. In this context, energy density, portion size, and habitual meal patterns have strong influences on energy intake and, accordingly, can be targeted to reduce energy intake. For example, energy density can be reduced without much affecting food reward (approximately the pleasure gained from eating) because their relationship is such that reward value is affected relatively little by increments in energy density above 1.5 kcal/g. This and other strategies that increase reward per calorie eaten may be superior to increasing the satiety effect of products because fullness is not inherently rewarding. Low-calorie sweeteners provide a means to reduce energy density while largely preserving food or beverage reward value. Consistent with this, consumption of low-calorie sweeteners compared with consumption of sugars has been found to reduce energy intake and body weight.

CONCLUSIONS

Understanding what causes excessive eating also provides insights into how to combat this problem.

The Impact of Nutrition and Health Claims on Consumer Perceptions and Portion Size Selection: Results from a Nationally Representative Survey

Nutrition and health claims on foods can help consumers make healthier food choices. However, claims may have a ‘halo’ effect, influencing consumer perceptions of foods and increasing consumption. Evidence for these effects are typically demonstrated in experiments with small samples, limiting generalisability. The current study aimed to overcome this limitation through the use of a nationally representative survey. In a cross-sectional survey of 1039 adults across the island of Ireland, respondents were presented with three different claims (nutrition claim = “Low in fat”; health claim = “With plant sterols. Proven to lower cholesterol”; satiety claim = “Fuller for longer”) on four different foods (cereal, soup, lasagne, and yoghurt). Participants answered questions on perceived healthiness, tastiness, and fillingness of the products with different claims and also selected a portion size they would consume. Claims influenced fillingness perceptions of some of the foods. However, there was little influence of claims on tastiness or healthiness perceptions or the portion size selected. Psychological factors such as consumers’ familiarity with foods carrying claims and belief in the claims were the most consistent predictors of perceptions and portion size selection. Future research should identify additional consumer factors that may moderate the relationships between claims, perceptions, and consumption.

Plate-clearing tendencies and portion size are independently associated with main meal food intake in women: A laboratory study

BACKGROUND

Larger portion sizes of food promote increased food intake, although the mechanisms explaining the portion size effect are unclear. In the present study we examined whether the tendency to clear one's plate when eating is associated with greater food intake in response to larger portion size.

METHOD

We recruited female participants who were either self-reported habitual plate clearers (N = 48) or non-plate clearers (N = 41) into a laboratory study. In a between-subjects design, participants were served either a 'normal' (500 g) or 'large' (1000 g) portion of pasta for lunch and ate as much as they desired.

RESULTS

There was no significant interaction found between portion size and plate-clearing tendencies; portion size had a similar sized effect on food intake in both plate clearers and non-plate clearers. A significant main effect of portion size was found, whereby participants consumed significantly more when served the large versus the normal portion (100.55 g difference, p < .001, η_p²  = 0.16). There was also a significant main effect of plate clearing; participants with a tendency to clear their plate when eating consumed significantly more than non-plate clearers (68.21 g difference, p = .006, η_p²  = 0.08).

CONCLUSIONS

The tendency to clear one's plate when eating was associated with increased food intake during a lunchtime meal. Increasing the portion size of the lunchtime meal increased food intake, although the tendency for a larger portion size to increase food intake was observed irrespective of participant plate-clearing tendencies.

An historical perspective on variety in United States dining based on menus

While food variety continues to be of major interest to those studying eating and health, research has been mainly limited to laboratory research of simple meals. This paper seeks to enlarge the scope of eating research by examining the food offered in the earliest menus in United States restaurants and hotels of the early and mid-19th c, when restaurants began. This reveals a very large variety in what food was offered. The paper discusses why variety has declined in the US and probably elsewhere, including changes in the customer, changes in food service, changes of food availability, and the industrialization of the food supply. Menu analysis offers another approach to studying dietary variety across cultures and across time.

Perceived impact of smaller compared with larger-sized bottles of sugar-sweetened beverages on consumption: A qualitative analysis

Sugar-sweetened beverage (SSB) consumption increases obesity risk and is linked to adverse health consequences. Large packages increase food consumption, but most evidence comes from studies comparing larger with standard packages, resulting in uncertainty regarding the impact of smaller packages. There is also little research on beverages. This qualitative study explores the experiences of consuming cola from smaller compared with larger bottles, to inform intervention strategies.

Sixteen households in Cambridge, England, participating in a feasibility study assessing the impact of bottle size on in-home SSB consumption, received a set amount of cola each week for four weeks in one of four bottle sizes: 1500 ml, 1000 ml, 500 ml, or 250 ml, in random order. At the study end, household representatives were interviewed about their experiences of using each bottle, including perceptions of i) consumption level; ii) consumption-related behaviours; and iii) factors affecting consumption. Interviews were semi-structured and data analysed using the Framework approach. The present analysis focuses specifically on experiences relating to use of the smaller bottles.

The smallest bottles were described as increasing drinking occasion frequency and encouraging consumption of numerous bottles in succession. Factors described as facilitating their consumption were: i) convenience and portability; ii) greater numbers of bottles available, which hindered consumption monitoring and control; iii) perceived insufficient quantity per bottle; and iv) positive attitudes. In a minority of cases the smallest bottles were perceived to have reduced consumption, but this was related to practical issues with the bottles that resulted in dislike.

The perception of greater consumption and qualitative reports of drinking habits associated with the smallest bottles raise the possibility that the ‘portion size effect’ has a lower threshold, beyond which smaller portions and packages may increase consumption. This reinforces the need for empirical evidence to assess the in-home impact of smaller bottles on SSB consumption.

Presenting a food in multiple smaller units increases expected satiety

Presentation of the same amount of a food in multiple smaller units (‘segmentation’) has been shown to reduce food intake and increase estimates of the amount of food consumed. However, this effect has been demonstrated for ad libitum food intake only. In the majority of cases, meals are not consumed ad libitum, but are pre-selected and consumed in their entirety, Expected satiety (ES; the anticipated capacity of a portion of food to relieve hunger between meals) is an excellent predictor of portion size selection. This study tested the hypothesis that segmentation increases ES. It was also hypothesised that perceived volume (PV) may account for the relationship between segmentation and ES. Sixty-eight participants made computer-based ES and PV judgments for equicaloric portions of three test foods (salted peanuts, spaghetti Bolognese, and chicken tikka masala), which were presented in either a single unit or as multiple smaller units (three or six units). Results revealed a consistent effect of segmentation on ES - foods presented in multiple smaller units were expected to deliver significantly greater satiety than when presented in a single unit (p < 0.005). Furthermore, results indicated that the effect of segmentation on ES was attributable to an increase in PV. ES plays an important role in determining the portion sizes that people select. Therefore, awareness of the effect of segmentation on ES may help to inform the design of foods that confer benefits for healthy weight maintenance.

What can the food and drink industry do to help achieve the 5% free sugars goal?

AIMS

To contribute evidence and make recommendations to assist in achieving free sugars reduction, with due consideration to the broader picture of weight management and dietary quality.

METHODS

An expert workshop in July 2016 addressed options outlined in the Public Health England report 'Sugar reduction: The evidence for action' that related directly to the food industry. Panel members contributed expertise in food technology, public heath nutrition, marketing, communications, psychology and behaviour. Recommendations were directed towards reformulation, reduced portion sizes, labelling and consumer education. These were evaluated based on their feasibility, likely consumer acceptability, efficacy and cost.

RESULTS

The panel agreed that the 5% target for energy from free sugars is unlikely to be achievable by the UK population in the near future, but a gradual reduction from average current level of intake is feasible. Progress requires collaborations between government, food industry, non-government organisations, health professionals, educators and consumers. Reformulation should start with the main contributors of free sugars in the diet, prioritising those products high in free sugars and relatively low in micronutrients. There is most potential for replacing free sugars in beverages using high-potency sweeteners and possibly via gradual reduction in sweetness levels. However, reformulation alone, with its inherent practical difficulties, will not achieve the desired reduction in free sugars. Food manufacturers and the out-of-home sector can help consumers by providing smaller portions. Labelling of free sugars would extend choice and encourage reformulation; however, government needs to assist industry by addressing current analytical and regulatory problems. There are also opportunities for multi-agency collaboration to develop tools/communications based on the Eatwell Guide, to help consumers understand the principles of a varied, healthy, balanced diet.

CONCLUSION

Multiple strategies will be required to achieve a reduction in free sugars intake to attain the 5% energy target. The panel produced consensus statements with recommendations as to how this might be achieved.

Expectations of food satiation and satiety reviewed with special focus on food properties

Expectations of satiation are beliefs about the extent to which food is expected to deliver fullness and expectation of satiety relates to the extent to which food is expected to give respite from hunger and to inhibit further eating.