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

Eating vegetables at school lunchtimes: Pilot and feasibility studies testing strategies to improve intake

Vegetable provision at schools in the UK has increased over recent years; however children still eat few of the vegetables that are served to them. Two experimental pilot and feasibility studies implemented a vegetables-served-first (study 1) plus experiential learning (study 2) approach to increase children's (3-5 years and 4-7 years respectively) vegetable consumption at school lunchtimes. Both studies involved vegetables-served-first 10-min before the rest of the meal, with experiential learning techniques (repeated exposure, "veg-first" dinner plates, vegetable songs, videos, and nutrition education) complementing the vegetable service in study 2. Study 1 (n = 38) found that vegetables-served-first, compared with serving all foods together, increased vegetable intake by ∼12 g. Study 2 (n = 69) found that vegetable consumption depended on individual schools. Schools where vegetable intake was low showed increases in consumption during intervention weeks, whereas schools with high vegetable intake showed little change. Acceptability of interventions was found to be good for children and schools that participated, although concerns about time to serve vegetables first and COVID-related environmental restrictions reduced feasibility for some schools. Child engagement could also be improved by offering a wider variety of vegetables during repeated exposure to reduce monotony. Future research should design interventions using co-design methods including schools to suit their context best, whilst also addressing the problem with a systems approach. Interventions which focus on child learning through experience need to take account of specific school environments including curricular needs, resources available for school lunch (including both time and space), provision of food, support from teachers and parents, and the culture around eating (e.g. encouragement, pressure to eat, lunchtime competing with playtime). Joined-up systems approaches could enhance both provision and uptake of vegetables at school meals.

PACE: a Novel Eating Behavior Phenotype to Assess Risk for Obesity in Middle Childhood

BACKGROUND

Behavioral phenotypes that predict future weight gain are needed to identify children susceptible to obesity.

OBJECTIVES

This prospective study developed an eating behavior risk score to predict change in adiposity over 1 y in children.

METHODS

Data from 6 baseline visits (Time 1, T1) and a 1-y follow-up visit (Time 2, T2) were collected from 76, 7- to 8-y-old healthy children recruited from Central Pennsylvania. At T1, children had body mass index (BMI) percentiles <90 and were classified with either high (n = 33; maternal BMI ≥30 kg/m2) or low (n = 43; maternal BMI ≤25 kg/m2) familial risk for obesity. Appetitive traits and eating behaviors were assessed at T1. Adiposity was measured at T1 and T2 using dual-energy x-ray absorptiometry, with a main outcome of fat mass index (FMI; total body fat mass divided by height in meters squared). Hierarchical linear regressions determined which eating measures improved prediction of T2 FMI after adjustment for covariates in the baseline model (T1 FMI, sex, income, familial risk, and Tanner stage).

RESULTS

Four eating measures-Portion susceptibility, Appetitive traits, loss of control eating, and eating rate-were combined into a standardized summary score called PACE. PACE improved the baseline model to predict 80% variance in T2 FMI. PACE was positively associated with the increase in FMI in children from T1 to T2, independent of familial risk (r = 0.58, P < 0.001). Although PACE was higher in girls than boys (P < 0.05), it did not differ by familial risk, income, or education.

CONCLUSIONS

PACE represents a cumulative eating behavior risk score that predicts adiposity gain over 1 y in middle childhood. If PACE similarly predicts adiposity gain in a cohort with greater racial and socioeconomic diversity, it will inform the development of interventions to prevent obesity. This trial was registered at clinicaltrials.gov as NCT03341247.

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

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

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

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

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.

The Cerebellar Response to Visual Portion Size Cues Is Associated with the Portion Size Effect in Children

The neural mechanisms underlying susceptibility to eating more in response to large portions (i.e., the portion size effect) remain unclear. Thus, the present study examined how neural responses to portion size relate to changes in weight and energy consumed as portions increase. Associations were examined across brain regions traditionally implicated in appetite control (i.e., an appetitive network) as well as the cerebellum, which has recently been implicated in appetite-related processes. Children without obesity (i.e., BMI-for-age-and-sex percentile < 90; N = 63; 55% female) viewed images of larger and smaller portions of food during fMRI and, in separate sessions, ate four meals that varied in portion size. Individual-level linear and quadratic associations between intake (kcal, grams) and portion size (i.e., portion size slopes) were estimated. The response to portion size in cerebellar lobules IV-VI was associated with the quadratic portion size slope estimated from gram intake; a greater response to images depicting smaller compared to larger portions was associated with steeper increases in intake with increasing portion sizes. Within the appetitive network, neural responses were not associated with portion size slopes. A decreased cerebellar response to larger amounts of food may increase children's susceptibility to overeating when excessively large portions are served.

School lunch portion sizes provided for children attending early years settings within primary schools: A cross-sectional study

BACKGROUND

In England, many children attend an early years' setting (EYS) that is part of a primary school. Where a school lunch is available, this is often the same for both EYS and school children. This study explored how school lunch portion sizes served for 3-4-year-old EYS children compared with portion size guidance for EYS and schools, given that recommendations are different for EYS and school-aged children.

METHODS

Twelve schools were recruited in four local authorities, each of which provided a school lunch to children attending EYS (aged 3-4 years) and reception classes (aged 4-5 years) from the same menu. Two portions of each menu item were weighed, each day, for five consecutive days. Mean, median, standard deviation and correlation coefficient were calculated for each food item.

RESULTS

Most caterers reported serving the same-sized portions to both 3-4-year-olds and 5-7-year-olds. Food items falling outside of the typical range for EYS were more commonly above the range (10 food items) than below it (6 food items). Notably, portions of cakes and biscuits were larger than recommended. Portion weights falling outside of the recommended range for 4-10-year-olds were usually too small (12 of 14 items). Some foods provided by the schools in the study did not have typical portion sizes for EYS as they were not 'good choices of foods to serve'.

CONCLUSIONS

These results suggest caterers may not be following guidelines appropriate for all the children they are catering for.

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

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

Risk Factors for Overweight and Obesity within the Home Environment of Preschool Children in Sub-Saharan Africa: A Systematic Review

Sub-Saharan Africa (SSA) is experiencing an increasing prevalence of young children being overweight and obese. Many feeding and physical activity-related behaviours are established at home during preschool years, yet the precise factors that contribute to preschool overweight and obesity have not been fully elucidated. This review aims to identify factors in the home environment associated with overweight and or obesity in preschool children in SSA. Ovid MEDLINE, EMBASE, CINAHL, Scopus, Web of Science, Africa Journals Online (AJOL) and the African Index Medicus databases were systematically searched for qualitative and quantitative studies published between 2000 and 2021. Eleven studies (ten quantitative, one qualitative) met the inclusion criteria. Overall, the results highlight the paucity of studies exploring factors in the home environment associated with overweight and obesity in preschool children in Sub-Saharan Africa. The home food environment and maternal BMI appear to be important factors associated with overweight and obesity in preschool children; however, the information for all other factors explored remains unclear due to the lack of evidence. For successful obesity prevention and treatment interventions to be developed, more research in this area is required to understand how different aspects of the home environment contribute to overweight and obesity in preschool Sub-Saharan African children.

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

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

Portion size can be used strategically to increase intake of vegetables and fruits in young children over multiple days: a cluster-randomized crossover trial

BACKGROUND

Although dietary guidelines recommend that vegetables and fruits make up half the diet, it is unclear whether serving vegetables and fruits in larger portions will have sustained effects on children's intake over multiple days.

OBJECTIVES

This study tested the effects on children's intake of 2 strategies for increasing the proportion of vegetables and fruits: either adding or substituting extra portions as side dishes at meals and snacks over 5 d.

METHODS

In a cluster-randomized crossover design with 3 periods, we provided all meals and snacks for 5 d to 53 children aged 3-5 y in classrooms in their childcare centers. In the Control condition, we served typical portions for all food groups. In the Addition condition we increased portions of low-energy-dense vegetables and fruits by 50%, and in the Substitution condition we increased portions of vegetables and fruits by 50% and also reduced portions of other foods by an equivalent weight.

RESULTS

For vegetables, the Addition strategy increased daily intake compared with Control by 24% (mean ± SEM = 12 ± 3 g/d; P = 0.0002), and the Substitution strategy increased intake compared with Control by 41% (22 ± 3 g/d; P < 0.0001). For fruits, consumption increased by similar amounts: Addition by 33% (60 ± 6 g/d) and Substitution by 38% (69 ± 8 g/d; both P < 0.0001). Both strategies increased vegetable and fruit intakes compared with Control across all 5 days (all P < 0.004), although the increase in fruit consumption with Addition declined over time (P < 0.0001). Daily energy intake compared with Control increased by 5% with Addition (57 ± 17 kcal; P = 0.001) but decreased by 6% with Substitution (-64 ± 21 kcal; P = 0.004).

CONCLUSIONS

Both the Addition and Substitution strategies promoted increases in vegetable and fruit intake over 5 d in preschool children. When excess energy intake is a concern, substituting vegetables and fruits for other foods is a better option than simply serving more.This trial was registered at http://www.clinicaltrials.gov as NCT03242863 (https://clinicaltrials.gov/ct2/show/NCT03242863), where the protocol is available.

Grandparental dietary provision, feeding practices and feeding styles when caring for preschool-aged grandchildren: A systematic mixed methods review

Grandparents are frequently relied upon to care for their preschool-aged grandchildren. These early years are a crucial age in the development of dietary habits and preferences. This review aims to determine grandparental dietary provision, feeding practices and feeding styles when caring for their preschool-aged grandchildren. Medline, PsycInfo and Web of Science were searched in January 2020. A systematic mixed methods approach was used to synthesize the qualitative (n = 13) and quantitative (n = 7) articles describing grandparents' feeding styles (n = 9), feeding practices (n = 14) and dietary provision (n = 18). Grandparents are serving large portion sizes and encouraging their grandchildren to eat frequently. Results are mixed for the types of foods provided; grandparents provide discretionary foods high in sugar and fat, and some also choose more expensive core foods as treats (e.g., berries). Grandparents engage in feeding practices that promote healthy eating (e.g., creating a healthy feeding environment) and promote autonomy and independence (e.g., considering their grandchild's preferences). However, they also use some coercive feeding practices (e.g., using food as a reward) and may be using indulgent feeding styles, which can be conducive to obesogenic dietary intakes. Interventions targeting grandparents could be an effective way to improve dietary-related health outcomes in young children.

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.

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

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

Current Systems-Level Evidence on Nutrition Interventions to Prevent and Treat Cardiometabolic Risk in the Pediatric Population: An Evidence Analysis Center Scoping Review

Improving and maintaining cardiometabolic health remains a major focus of health efforts for the pediatric population. Recent research contributes understanding of the systems-level nutrition factors influencing cardiometabolic health in pediatric individuals. This scoping review examines current evidence on interventions and exposures influencing pediatric cardiometabolic health to inform registered dietitian nutritionists working at each systems level, ranging from individual counseling to public policy. A literature search of MEDLINE, CINAHL, Cochrane Databases of Systematic Reviews, and other databases was conducted to identify evidence-based practice guidelines, systematic reviews, and position statements published in English from January 2017 until April 2020. Included studies addressed nutrition interventions or longitudinal exposures for participants 2 to 17 years of age who were healthy or had cardiometabolic risk factors. Studies were categorized according level of the social-ecological framework addressed. The databases and hand searches identified 2614 individual articles, and 169 articles were included in this scoping review, including 6 evidence-based practice guidelines, 141 systematic reviews, and 22 organization position statements. The highest density of systematic reviews focused on the effects of dietary intake (n = 58) and interventions with an individual child or family through counseling or education (n = 54). The least frequently examined levels of interventions or exposures were at the policy level (n = 12). Registered dietitian nutritionists can leverage this considerable body of recent systematic reviews to inform a systems-level, collaborative approach to prevention and treatment of pediatric cardiometabolic risk factors.

What guidance is there on portion size for feeding preschool-aged children (1 to 5 years) in the United Kingdom and Ireland? A systematic grey literature review

Large portion sizes of food can lead to excessive energy intake and weight gain in young children. Although portion size guidance is available, parents are often unaware it exists. Our systematic grey literature review aimed to identify the portion size guidance resources in the United Kingdom and Ireland, aimed at users (e.g., parents and childcare providers) responsible for feeding preschool-aged children. We describe who the resources are aimed at, how they are informed and whether the recommended portion sizes are consistent across resources. Resources were identified via advanced Google searches, searching reference lists and contacting experts. Resources that provided quantifiable portion size information (e.g., grammes) were included. Portion sizes (g) were extracted and energy equivalents (kcal) were calculated. Portion sizes were analysed by food group and by eating occasion. Twenty-two resources were identified. Median portion sizes were consistent across resources for fruit (40 g [IQR = 40-50]) and vegetables (40 g [IQR = 30-40]). Variability was observed in portion size and/or energy content for dairy (60 g [IQR = 25-93]), protein (72 kcal [IQR = 44-106]) and starchy (41 g/71 kcal [IQR = 25-80/56-106]) food groups. The range in size of an average eating occasion was large (90-292 g). This review identifies resources that could help caregivers to choose appropriate portion sizes for preschool-aged children but also highlights how future resources could be improved.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Nutritional assessment of the school menus offered in Spain's Mediterranean area

OBJECTIVES

The aim of this study was to perform a nutritional assessment of the menus served in school canteens and to verify their effects on the nutrition of schoolchildren.

METHODS

We selected three collective catering companies that offered ~53 500 menus/d in 369 schools in Spain's Mediterranean area (Valencian Community). The study included four public schools with different management models as well as different supply patterns. Considering the weight of the servings, the caloric contribution of the menus was estimated.

RESULTS

Great diversity was seen both in the same school throughout the week and between the four schools (School 1: 298-946 kcal; School 2: 465-1185 kcal; School 3: 395-656 kcal; and School 4: 374-966 kcal). The energy intake from carbohydrates complied with the recommendations in three of the four schools, the energy provided from proteins was adequate in all of the schools, and the energy from lipids was higher than the recommended values in Schools 1 and 2, lower in School 3, and compliant in School 4. The most abundant fatty acids in the menus were oleic, linoleic, and palmitic acids. The sodium content in the rated menus was 229 ± 72 mg/100 g. The highest salt content came from menus that included a precooked dish, processed meat, or both.

CONCLUSION

It is necessary to review school menus and adjust the size of the servings to the age of the children. Correct nutritional education is essential for both kitchen staff and school canteen monitors.

Portion size selection in children: Effect of sensory imagery for snacks varying in energy density

Food sensory imagery - creating a vivid mental image of the sensory experience of eating - can lead to the selection of smaller portions because it serves as a reminder that eating enjoyment does not necessarily increase with portion size. The evidence is mostly limited to adults and to energy-dense foods for which it is particularly difficult to predict the satiating effects of consumption quantity. The objective was to study how food sensory imagery influences portion size selection of foods varying in energy density (brownie and applesauce) by 7- to 11-year-old children. During after-school time, 171 children were randomized into two conditions. Children in the food sensory imagery condition were asked to imagine the taste, smell, and texture of eating palatable foods, i.e., chocolate cereal, chocolate waffle, and chocolate candies. Children in the control condition performed a similar sensory imagery task for non-food-related activities. Children were then asked to choose between the recommended serving size, a 50% larger portion, and a 125% larger portion of either brownie or applesauce. One week later, they were placed in the same condition for the other food. Compared to the control condition, food sensory imagery led children to choose 7.1% less brownie but had no effect on applesauce portion selection. Exploratory findings showed that the food sensory imagery intervention was especially effective at reducing brownie portion size selection among children who were moderately hungry, who usually eat fast, and whose parents pressure them to eat. In conclusion, food sensory imagery may be a useful intervention to nudge children towards healthier portion size choices because it reduces the selected portion size of an energy-dense snack without reducing the selected portion size of a healthier snack.

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.