The portion size effect and overconsumption – towards downsizing solutions for children and adolescents – An update

The portion size effect (PSE), where more is eaten when large amounts are offered, is robust, reliable and enduring. Although it is not known what drives the PSE, amount served may act as a guide to how much should be eaten. Over time, consumers become accustomed to particular amounts of food as the ‘social norm’ and so large portion sizes are treated as typical. For children and adolescents who are forming eating habits, long‐term exposure to large portion sizes of snacks and meal items may encourage overconsumption. Therefore, offering smaller portions to suit the age and stage of children and young people should offer a potential solution to the PSE. We have developed a series of downsizing strategies to test the effect of providing smaller portions of snacks and meal items in pre‐school children, adolescents and families. One potential consequence of downsizing is that compensation may occur, in which smaller portion sizes drive intake of other foods. Therefore, in examining downsizing strategies, measures of compensation elsewhere in the meal or across the overall diet are important. Our studies indicate that it is both feasible and desirable to offer ‘me‐sized’, smaller portions for children to facilitate portion control as food preferences and eating habits are developed. However, strategies for young adults and adolescents are more challenging and require further investigation

Variability in children's eating response to portion size. A biobehavioral perspective

The portion size of foods and beverages offered at meals has been shown to significantly affect human food intake. While portion size effects appear to be fairly robust across studies in adults, findings from studies in children are generally more variable and do not reliably predict a significant portion size effect. Eating behaviors are still forming at a young age and individual differences in children's response to portion size will depend upon genetic predisposition interacting with the child's environment. The aim of this review is to present and discuss evidence that innate controls of appetite and eating, which involve genes that encode key hormones and neuropeptides implicated in processes of satiety and satiation, may differentially affect meal size. We also present evidence that children's response to portion size is learned and this is in turn shaped by upbringing, the early family and home environment. The review will conclude with a conceptual model that illustrates how biological and environmental factors may interact to shape child eating traits including a behavioral susceptibility to overeating when large portion sizes are available

The portion size effect : women demonstrate an awareness of eating more than intended when served larger than normal portions

Large portion sizes lead to increased intake. Some studies suggest that individuals are unaware that they consume more when served larger portions. In a between-subjects design we asked female participants (N = 48) how much pasta and tomato sauce they intended to consume for lunch prior to eating. We then provided a smaller or a larger portion of the same food and invited participants to self-serve a portion into a second bowl (same size in both conditions). After eating until comfortably full, participants were shown an image of the amount they had selected at the beginning of the meal. They were then asked whether they perceived having eaten more or less than this amount, and by how much more or less they had eaten. In total 46 responses were analysed. Of the participants who received the large portion and who ate more than intended, 77% (p = .029) correctly identified eating more. However, when participants were asked to indicate by how much they had eaten above or below their intended amount, those who ate more after receiving a larger portion underestimated their intake by 25% (p = .003). These findings suggest that greater intake from a larger portion is associated with an awareness of having eaten a large quantity combined with a failure to register the actual amount consumed (in the direction of underestimation). The latter might be attributed to an error associated with the visual estimation of volume

Determinants of Portion Size in Children and Adolescents: Insights from the UK National Diet and Nutrition Survey Rolling Programme (2008–2016)

Large portion sizes have been identified as contributing to overweight and obesity, particularly in children and adolescents. This study examined predictors of portion sizes of high energy snack foods eaten by children aged 1.5–18 years. Specifically, we examined whether portion sizes were adjusted for age, and what external features of the environment might be linked to large portion sizes. Portion sizes were derived from four-day food diaries that form the UK National Diet and Nutrition Survey. Diaries from 5942 children were examined and multilevel models were used to discover whether age, gender, location, time of day, household income, and watching TV while eating predicted portion sizes of savoury snacks, chocolate, confectionery and biscuits. Portion sizes of all the target foods were predicted by age. Boys had larger portions, and portion sizes were larger when target foods were consumed later in the day. Portion sizes were larger outside the home, for example in leisure venues, but the target foods were eaten more frequently in the home. As dietary patterns change to include more snack intake outside the home, these locations could be an important space to target for interventions for portion control

Increasing Intake of an Unfamiliar Vegetable in Preschool Children Through Learning Using Storybooks and Sensory Play: A Cluster Randomized Trial

Background: Most children eat fewer vegetables than recommended. Storybooks and sensory play may increase vegetable intake. Objective: This study tested the effects on intake of learning about an unfamiliar vegetable (celeriac) through storybooks and sensory play. It was predicted that an illustrated, congruent storybook would increase intake of celeriac compared to an incongruent storybook (carrot); and that adding congruent sensory play with celeriac to the storybook would produce a synergistic effect on intake of celeriac. Design: Children from 12 UK preschools were randomly assigned by clusters to four intervention conditions using a 2×2 factorial design. The factors were vegetable congruency (sensory play and/or storybook were congruent, or incongruent [carrot] with celeriac) and intervention type (storybook only or storybook combined with sensory play). Participants/setting: Three hundred and thirty-seven children aged 2 to 5 years were recruited to take part in November 2017. Intervention: Over a 2-week period, children in all four conditions were read a vegetable storybook featuring celeriac or carrot. In addition, two conditions received sensory play with either carrot or celeriac added to the storybook method. Main outcome measures: Intake of the unfamiliar vegetable (celeriac) was measured at baseline and after the 2-week intervention. Statistical analysis performed: Complex samples logistic regression and general linear modeling were performed to examine group differences at post-intervention. Results: Children receiving the congruent (celeriac) storybook had higher odds of eating celeriac compared to children who received the incongruent (carrot) storybook. Receiving congruent sensory play increased the odds of eating celeriac, whereas receiving incongruent sensory play did not. From the 267 children who completed both baseline and post-intervention assessments, 85 ate no celeriac at baseline and were classed as non-eaters. Sensory play (congruent or incongruent) increased the odds of eating some celeriac in non-eaters compared to storybook only conditions. Conclusions: Congruency between storybook and vegetable increased intake; sensory play with celeriac increased the likelihood of eating celeriac. Storybooks and sensory play are simple interventions to increase willingness to try an unfamiliar vegetable

Do maternal perceptions of child eating and feeding help to explain the disconnect between reported and observed feeding practices?: A follow-up study

Research demonstrates a mismatch between reported and observed maternal feeding practices. This mismatch may be explained by maternal cognitions, attitudes, and motivations relating to dyadic parent–child feeding interactions. These complex constructs may not be apparent during observations nor evidenced in self-report questionnaire. Therefore, the aim of this study was to use a qualitative approach to gain a more nuanced and contextualized understanding of (a) maternal perceptions of children's food intake control; (b) how parent–child mealtime interactions influence maternal feeding practices; and (c) ways in which mothers may promote healthy child eating and weight outcomes. Semistructured telephone interviews were conducted with 23 mothers (M = 38.4 ± 3.7 years of age) of preschool-aged children (M = 3.8 ± 0.6 years of age, 19 were normal weight, 14 were girls), who had previously completed child feeding questionnaire and participated in two home-based mealtime observations, 12 months apart. Interviews were recorded, transcribed, and themes extracted to create the database. Four major themes emerged: (a) Maternal confidence in children's ability to regulate food intake is variable; (b) Implementing strategies for nurturing healthy relationships with food beyond the dining table; (c) Fostering positive mealtime interactions is valued above the content of what children eat; and (d) Situation-specific practices and inconsistencies. Findings indicate that maternal feeding practices are shaped by both parent and child influences, and child feeding is mostly guided by controlling the family food environment, rather than by directly pressuring or restricting their child's eating. Results also highlighted the need for research to consider both parent and child influences on child feeding

The effect of food type on the portion size effect in children aged 2-12 years: A systematic review and meta-analysis.

Visual cues such as plate size, amount of food served and packaging are known to influence the effects of portion size on food intake. Unit bias is a well characterised heuristic and helps to determine consumption norms. In an obesogenic environment where large portions are common place, the unit or segmentation bias may be overridden promoting overconsumption of both amorphous or unit foods. The aim of this review was to investigate the impact of offering unit or amorphous food on the portion size effect (PSE) in children aged 2–12 years. A systematic search for literature was conducted in Medline, PsycInfo and Web of Science in February 2018. A total of 1197 papers were retrieved following the searches. Twenty-one papers were included in the systematic review, of which 15 provided requisite statistical information for inclusion in a random effects meta-analysis. Increasing children's food portion size by 51–100% led to a significant increase in intake (SMD = 0.47, 95% CI: 0.39–0.55). There was no evidence to suggest that increases in consumption were related to food type (p = 0.33), child age (p = 0.47) or initial portion size served (p=0.14). Residual heterogeneity was not significant (p=0.24). The PSE was demonstrated in children aged 2–12 years when offered both unit and amorphous food items. The effect was not restricted by food type, child age or influenced by initial portion size served. Of the studies included in the meta-analysis between study heterogeneity was low suggesting minimal variation in treatment effects between studies, however, more research is required to understand the mechanisms of the PSE in preschool children. Future research should determine feasible methods to downsize portion sizes served to children

Attention to detail: A photo‐elicitation study of salience and packaging design for portion control and healthy eating

Evidence demonstrates that food packaging attracts consumers to purchase and has the potential to nudge consumers towards healthy choices, including reducing portion size. However, food purchasing decisions are often automatic and packaging features may go unnoticed. Therefore, it is important to understand what consumers identify as most salient about packaging: what they notice and why, and which elements might nudge consumers towards healthy options and smaller portions of high-energy-density foods. This study explored consumer perception of food packaging, investigated specific features associated with portion control and elicited design ideas to improve packaging for healthy eating and downsizing. A qualitative approach was adopted applying a participant-driven photo-elicitation (PDPE) task with in-depth interviews. Participants were 25 adults living in the UK (aged 20–32 years; 17 females, 8 males, x BMI = 23 kg/m2). Participants took photographs of 10 food packages according to salience (n = 5) and portion control (n = 5). These were uploaded to a secure site and then discussed at the interview, which was transcribed and analysed. The salience of packaging was described in terms of trust building, stimulating appetite and relating to self-identity, whereas for portion control, themes included structural reminders, healthy prompts and portion awareness. Packaging can be designed to make health value or serving size more salient by prompting portion control and increasing the attractiveness of packaging. While food purchase decisions happen with little deliberation, when probed, consumers provide useful insights for packaging design to assist portion control

The eyes have it: Infant gaze as an indicator of hunger and satiation

Infant gaze serves as a measure of attention to food cues in adults and children and may play a role in signalling infant hunger and satiation. Maternal responsiveness to infant satiation cues, including gaze, supports healthy appetite development and may reduce obesity risk. However, mothers often experience difficulty in interpreting feeding cues, and there have been few attempts to study cues systematically. This study aimed to develop a reliable coding scheme for categorising and tracking infant gaze behaviours during complementary feeding (CF). Twenty infants aged between six and eighteen months were filmed during typical meals on two occasions at home. The Infant Gaze at Mealtime (IGM) coding scheme was devised from the analysis of a sample of videos, a piloting and testing process, and the feeding cues and developmental psychology literature. Inter and intra-rater reliability tests of the scheme with 20% of the study videos revealed high levels of reliability. When applied to the full sample of 225 video clips, the IGM coding scheme revealed a significant decrease over time in the frequency of infants gazing at food and a significant increase in exploratory gaze behaviour within a meal. These changes were consistent across main and dessert courses, suggesting they may be indicative of changes in infant feeding state. The results suggest that infant gaze may offer a means of identifying infant hunger and satiation and, as an easily observed behaviour, an effective tool for mothers and professionals for promoting responsive feeding