Daily energy balance in children and adolescents. Does energy expenditure predict subsequent energy intake?

Impact of physical activity on caloric and macronutrient intake in children and adolescents: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Physical activity is widely promoted to maintain and improve health across all ages. Investigating how physical activity affects subsequent food intake provides insight into the factors that contribute to maintaining energy balance and effective weight management.

OBJECTIVE

This systematic review and meta-analysis summarizes the evidence on the effect of acute physical activity on subsequent food intake in children and adolescents.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA) were applied. Randomized controlled trials (RCTs) objectively measuring post-exercise energy intake in children and adolescents aged 5 to 18 years were included. Studies with self-reported food intake were excluded. The databases PubMed, Web of Science and Cochrane Library were searched for RCTs, and the data were summarized at a qualitative and quantitative level. Version 2 of the Cochrane risk-of-bias tool for randomized trials was used to assess risk of bias. Changes in energy intake were examined with random effects meta-analysis. (PROSPERO: CRD42022324259).

RESULTS

Out of 9582 studies, 22 RCTs with cross-over design remained eligible for meta-analysis. The primary outcome was post-intervention energy intake up to the next 24 h. Heterogeneity of studies was moderate, with an I2 of 57%. The median (interquartile range, IQR) energy expended while exercising was 240 (158) kcal. Meta-analysis of 41 study arms (exercise n = 780 and control n = 478) showed no differences in total energy intake between the exercise and control group with a mean difference MD = 23.31 [-27.54, 74.15] kcal. No subgroup differences were found. Macronutrient intake and appetite sensations where not substantially affected.

CONCLUSION

Engaging in exercise is a suitable means of raising activity-induced energy expenditure, without causing any noticeable changes in food intake or hunger within a single day.

A study on the configuration of factors influencing overweight and obesity in adolescents based on fuzzy set qualitative comparative analysis

OBJECTIVE

Overweight and obesity among adolescents are grave public health issues around the world. Although the conditions that contribute to obesity have been extensively researched, little is known about how multiple conditions interact to cause overweight and obesity. The current study intends to investigate the histomorphic configuration pathways of several conditions of adolescent overweight and obesity by gender.

METHOD

The data came from a social survey conducted in June 2021 in Changchun, Jilin Province, China. The sample collected was 14-year-old adolescents, including 167 boys and 137 girls. The school physicians examined the participants' weight and height, and questionnaires were used to collect risk indicators from adolescents, such as sleep duration, electronic screens times, consumption of sugary drinks and fried foods, and physical activity. Simultaneously, a Fuzzy Qualitative Comparative Analysis will be performed to investigate the combinations of diverse conditions.

RESULT

We found that there is no determining necessary condition that, once present, directly determines that an individual is in a state of overweight and obesity. Simultaneously, this study revealed nine alternative configurational paths of overweight and obesity in teenagers of different genders, with a concordance of 0.805 for six male groupings and 0.916 for three female groupings. The outcomes of overweight obesity in adolescents under different genders are similar but not identical.

CONCLUSION

This study examined the interactions of a number of conditions from the individual, behavioral, learning and living environment that led to the same overweight obese outcome among adolescents of different genders. Our research will be useful to policymakers in that interventions should take into account the combined effects of a number of different aspects rather than focusing on a single factor that causes overweight and obesity.

The long-term effects of primary school-based obesity prevention interventions in children: A systematic review and meta-analysis

INTRODUCTION

This systematic review and meta-analysis investigate the long-term effects of primary school-based obesity prevention interventions on body-mass index (and z-scores), waist circumference (and z-scores) and weight status.

METHODS

Four databases were searched for studies from date of inception until June 8th, 2021. We included randomized controlled trials (RCT) and non-RCTs investigating effects ≥12 months post-intervention of primary school-based interventions with intervention duration ≥6 months and containing a diet and/or physical activity component on outcomes of interest. Articles were assessed on risk of bias and methodological quality by RoB2 and ROBINS-I. Meta-analysis was performed and results were narratively summarized. Evidence quality was assessed with GRADE.

RESULTS

Nineteen studies were included, 9 were pooled in a meta-analysis. No long-term effects were found on body-mass index (+0.06 kg/m² ; CI95% = -0.38, 0.50; I²  = 66%), body-mass index z-scores (-0.08; CI95% = -0.20, 0.04; I²  = 36%), and waist circumference (+0.57 cm; CI95% = -0.62, 1.75; I²  = 13%). Non-pooled studies reported mixed findings regarding long-term effects on body-mass index, body-mass index z-scores and weight status, and no effects on waist circumference and waist circumference z-scores. Evidence certainty was moderate to very low.

DISCUSSION

No clear evidence regarding long-term effects of primary school-based interventions on obesity-related outcomes was found. Recommendations for further research and policy are discussed. Prospero registration ID: CRD42021240446.

Associations among affect, diet, and activity and binge-eating severity using ecological momentary assessment in a non-clinical sample of middle-aged fathers

PURPOSE

Knowledge of within-day factors associated with binge-eating severity among middle-aged fathers is limited. The purpose of the current report was to examine within-day associations of affect, diet, and activity in relation to binge-eating severity using ecological momentary assessment (EMA) in men.

METHODS

Twenty-three middle-aged fathers completed 8 days of EMA and wore accelerometers to objectively assess activity. Generalized estimating equations assessed relationships among affect, diet, and activity and binge-eating severity.

RESULTS

When positive affect was above average, men reported greater binge-eating severity in the next 2 h. Oppositely, when negative affect was above average, men reported less binge-eating severity in the next 2 h. At times when men reported consumption of sweets and fast food, they reported higher binge-eating severity during the same 2-h window. Men with greater average levels of light activity reported less overall binge-eating severity.

CONCLUSIONS

Findings show that affect, unhealthy food intake, and light activity could be targeted among middle-aged fathers to reduce binge-eating severity and prevent eating disorders.

LEVEL OF EVIDENCE

Level III: Evidence obtained from cohort or case-control analytic studies.

Effects of Movement Behaviors on Overall Health and Appetite Control: Current Evidence and Perspectives in Children and Adolescents

PURPOSE OF REVIEW

To present the definitions and recommendations for movement behaviors in children and adolescents, including physical activity (PA), sedentary behaviors (SB), and sleep, and to provide an overview regarding their impact on health and obesity outcomes from childhood to adulthood, as well as interactions with appetite control.

RECENT FINDINGS

PA represents a variable proportion of daily energy expenditure and one can be active with high SB or vice versa. Studies have described movements across the whole day on a continuum from sleep to SB to varying intensities of PA. More PA, less SB (e.g., less screen time) and longer sleep are positively associated with indicators of physical health (e.g., lower BMI, adiposity, cardiometabolic risk) and cognitive development (e.g., motor skills, academic achievement). However, less than 10% of children currently meet recommendations for all three movement behaviors. Movement behaviors, adiposity, and related cardiometabolic diseases in childhood track into adolescence and adulthood. Furthermore, low PA/high SB profiles are associated with increased energy intake. Recent studies investigating energy balance regulation showed that desirable movement behavior profiles are associated with better appetite control and improved eating habits. Early identification of behavioral phenotypes and a comprehensive approach addressing all key behaviors that directly affect energy balance will allow for individual strategies to prevent or treat obesity and its comorbidities. Investigating exercise as a potential "corrector" of impaired appetite control offers a promising weight management approach.

The food and nutrient intake of 5- to 12-year-old Australian children during school hours: a secondary analysis of the 2011-2012 National Nutrition and Physical Activity Survey

OBJECTIVE

School food intake of Australian children is not comprehensively described in literature, with limited temporal, nationally representative data. Greater understanding of intake at school can inform school-based nutrition promotion. This study aimed to describe the dietary intake of primary-aged children during school hours and its contribution to daily intake.

DESIGN

This secondary analysis used nationally representative, cross-sectional data from the 2011 to 2012 National Nutrition and Physical Activity Survey. Dietary intake was assessed using validated 24-h dietary recalls on school days. Descriptive statistics were undertaken to determine energy, nutrients, food groups and food products consumed during school hours, as well as their contributions to total daily intake. Associations between school food intake and socio-demographic characteristics were explored.

SETTING

Australia.

PARTICIPANTS

Seven hundred and ninety-five children aged 5-12 years.

RESULTS

Children consumed 37 % of their daily energy and 31-43 % of select nutrient intake during school hours, with discretionary choices contributing 44 % of school energy intake. Most children consumed less than one serve of vegetables, meat and alternatives or milk and alternatives during school hours. Commonly consumed products were discretionary choices (34 %, including biscuits, processed meat), bread (17 %) and fruit (12 %). There were limited associations with socio-economic position variables, apart from child age.

CONCLUSIONS

Children's diets were not aligned with national recommendations, with school food characterised by high intake of discretionary choices. These findings are consistent with previous Australian evidence and support transformation of the Australian school food system to better align school food consumption with recommendations.

The Effectiveness of School-Based Interventions on Obesity-Related Behaviours in Primary School Children: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

School-based interventions are promising for targeting a change in obesity-related behaviours in children. However, the efficacy of school-based interventions to prevent obesity remains unclear. This review examined the effectiveness of school-based interventions at changing obesity-related behaviours (increased physical activity, decreased sedentary behaviour and improved nutrition behaviour) and/or a change in BMI/BMI z-score. Following PRISMA guidelines, seven databases were systematically searched from 1 January 2009 to 31 December 2020. Two review authors independently screened studies for eligibility, completed data extraction and assessed the risk of bias of each of the included studies. Forty-eight studies met the inclusion criteria and were included in a narrative synthesis. Thirty-eight studies were eligible for inclusion in a meta-analysis. The findings demonstrate that interventions in children when compared to controls resulted in a small positive treatment effect in the control group (2.14; 95% CI = 0.77, 3.50). There was no significant effect on sedentary behaviour, energy intake and fruit and vegetable intake. Significant reductions were found between groups in BMI kg/m2 (-0.39; 95% CI = -0.47, -0.30) and BMI z-score (-0.05; 95% CI = -0.08, -0.02) in favour of the intervention. The findings have important implications for future intervention research in terms of the effectiveness of intervention components and characteristics.

Extracurricular Sports Participation and Sedentary Behavior in Association with Dietary Habits and Obesity Risk in Children and Adolescents and the Role of Family Structure: a Literature Review

PURPOSE OF REVIEW

Childhood obesity is considered a major problem in the modern world, associated with many health issues in youth. This review aimed the association between extracurricular sports participation, sedentary time/screen time, and "obesogenic" and "non-obesogenic" dietary habits among youth and to explore the role of family structure on the adoption of sedentary behaviors by children.

RECENT FINDINGS

Increased participation in extracurricular sports was associated with a healthier dietary pattern, containing more "non-obesogenic" food choices. Opposite results were indicated by sedentary activities. Increased time in watching TV, computer/electronic games, and other screen devices was positively associated with unhealthy dietary patterns. Overall, extracurricular activities influence the quality of food choices, which may prevent or promote childhood obesity; thus, sport-related activities should be promoted through public health policies. The role of the family structure is contradictory.

The Association Between Single-Child Status and Risk of Abdominal Obesity: Result From a Cross-Sectional Study of China

Background: Obesity has become a serious problem threatening the health of children and adolescents, and China's one-child policy has affected family structure and parenting practice, which may result in several adverse health outcomes. The present study aims to investigate the association between single-child status and the risk of abdominal obesity in Chinese adolescents and also to compare the differences in the risk of unideal energy-related behaviors. Methods: Data were obtained from a school-based cross-sectional survey conducted in seven provinces of China, in 2012. A total of 31,291 students aged 7-17 years were recruited in this study. Anthropometric measurements were conducted to assess height and waist circumference, and questionnaires were used to obtain information of single-child status, parental educational attainment, parental weight status, and offspring energy-related behaviors. Multivariate logistic regression models were used to estimate the odds ratio (OR) and 95% confidence intervals (95% CI) of single-child status and odds of childhood abdominal obesity and energy-related behaviors. Results: The prevalence of abdominal obesity was 18.2% in single children, which was higher than that of non-single children (13.7%). The prevalence was also higher in single children in different sex and residence subgroups. Logistic regression models showed that single children had 1.33 times (OR: 1.33, 95% CI: 1.24-1.43, P < 0.001) higher odds of abdominal obesity compared to non-single children. Single children had 1.08 times higher odds of physical inactivity (OR: 1.08, 95% CI: 1.03-1.14, P = 0.004), 1.13 times higher odds of excessive sugar-sweetened beverages (SSBs) consumption (OR: 1.13, 95% CI: 1.05-1.23, P = 0.002), and 1.08 times more likely to eat out (OR: 1.08, 95% CI: 1.02-1.13, P = 0.006). Those associations were more remarkable in single girls. Conclusion: Being a single child may be associated with a higher odds of childhood abdominal obesity and unhealthy energy-related behaviors. Future interventions and strategies to prevent abdominal obesity should focus on this high-risk population.

The EnergyKids Pilot Study: Comparing Energy Balance of Primary School Children during School and Summer Camp

Children's energy requirements may vary during school and summer camp days. To evaluate energy balance during these two periods, seventy-eight children (45% females, 8-10 years) living in Parma, Italy, were enrolled in this observational study. Participants completed a 3-day food diary and wore an activity tracker for three consecutive days during a school- and a summer camp-week to estimate energy intake (EI) and energy expenditure (TEE). Height and body weight were measured at the beginning of each period to define children's weight status. BMI and EI (school: 1692 ± 265 kcal/day; summer camp: 1738 ± 262 kcal/day) were similar during both periods. Both physical activity and TEE (summer camp: 1948 ± 312; school: 1704 ± 263 kcal/day) were higher during summer camp compared to school time. Therefore, energy balance was more negative during summer camp (-209 ± 366 kcal/day) compared to school time (-12 ± 331 kcal/day). Similar results were observed when males and females were analyzed separately but, comparing the sexes, males had a higher TEE and a more negative energy balance than females, during both periods. The results strongly suggest that an accurate evaluation of children's energy balance, that considers both diet and physical activity, is needed when planning adequate diets for different situations.

Energy intake and expenditure in children and adolescents, contributions of biological maturity

OBJECTIVE

The aim of this study was to examine the relationship between the ratio of energy intake (EI) and energy expenditure (EE) and body composition, physical activity and macronutrients intake, considering maturity as a moderator.

METHODS

The study involved 459 adolescents aged 10 to 17. Energy and macronutrients intake were estimated using a valid Food Frequency Questionnaire; basal metabolic rate (BMR) was predicted from Schofield equations and EE was estimated using BMR and physical activity level obtained through a Portuguese validated biosocial questionnaire. Body mass index, body composition, and bone age were objectively measured. Statistical analyses included independent samples t-tests, ANCOVA and Pearson correlations. All analyses were adjusted for chronological age, sex, and EI.

RESULTS

Body mass index, fat and fat-free mass, physical activity and protein intake were negatively correlated with EI/EE (P < .001). The study showed significant interactions between maturity and body mass index, fat-free mass and physical activity level. Maturity attenuated the negative relationships between EI/EE and body mass index, fat-free mass and physical activity, especially among early maturers. All categories of maturity showed implications in body mass index for values lower than 23.8 kg/m² . A significant EI/EE reduction was observed among late maturers with a fat-free mass above 39.8 kg.

CONCLUSIONS

Our findings suggest that maturity moderates the relationship between EI/EE and body mass index, fat-free mass and physical activity, especially evident among late maturers.

Pre-meal active video game playing increased subjective appetite but not food intake in children and adolescents

OBJECTIVE

Sedentary video game playing (VGP) and caloric preloads in the pre-meal environment have been shown to influence short-term food intake (FI) regulation in children. Other factors that may affect FI control include physical activity and/or heightened emotion. Therefore, we examined the effects of a glucose preload and 30 min of active VGP (aVGP) on subjective appetite, short-term FI, and subjective emotions in 9-14 year-old children.

METHODS

On four test mornings approximately one-week apart, twenty-seven children (sex: 15M, 12F; age: 11.3 ± 0.3 years; BMI percentile: 55.3 ± 6.1%) consumed a standardized breakfast two hours prior to consuming 250 mL of either a 50 g glucose preload or Sucralose® control. Following the preload, participants participated in 30 min of quiet sitting or aVGP. Energy expenditure was measured during aVGP via indirect calorimetry. FI from an ad libitum pizza meal was measured after each test condition. Subjective appetite and emotions were measured at baseline (0 min), during treatment (15min), and immediately before the test meal (30 min).

RESULTS

aVGP did not affect FI, but the glucose preload decreased FI compared with the sucralose control (∆ = 157 kcal, <0.001). Although not statistically significant (p=0.12), caloric compensation was lower following the glucose preload in the aVGP condition. Subjective appetite increased with time, and was higher in the sucralose control + aVGP condition (p=0.05). Change from baseline subjective emotion scores of anger and excitement were higher (p=0.03) and lower (p=0.02) after aVGP, respectively.

CONCLUSIONS

Neither short-term FI nor net energy balance were affected by low-intensity aVGP (energy expenditure of 34 kcal). These findings suggest that a short bout of low-intensity aVGP does not alter energy balance during the study measurement period, and may not support achieving or maintaining healthy weights in children. However, future longitudinal studies are needed to confirm such advice.

Projecting the impact of the coronavirus disease-2019 pandemic on childhood obesity in the United States: A microsimulation model

PURPOSE

The coronavirus disease-2019 (COVID-19) pandemic in the United States led to nationwide stay-at-home orders and school closures. Declines in energy expenditure resulting from canceled physical education classes and reduced physical activity may elevate childhood obesity risk. This study estimated the impact of COVID-19 on childhood obesity.

METHODS

A microsimulation model simulated the trajectory of a nationally representative kindergarten cohort's body mass index z-scores and childhood obesity prevalence from April 2020 to March 2021 under the control scenario without COVID-19 and under the 4 alternative scenarios with COVID-19-Scenario 1: 2-month nationwide school closure in April and May 2020; Scenario 2: Scenario 1 followed by a 10% reduction in daily physical activity in the summer from June to August; Scenario 3: Scenario 2 followed by 2-month school closure in September and October; and Scenario 4: Scenario 3 followed by an additional 2-month school closure in November and December.

RESULTS

Relative to the control scenario without COVID-19, Scenarios 1, 2, 3, and 4 were associated with an increase in the mean body mass index z-scores by 0.056 (95% confidence interval (95%CI): 0.055-0.056), 0.084 (95%CI: 0.084-0.085), 0.141 (95%CI: 0.140-0.142), and 0.198 (95%CI: 0.197-0.199), respectively, and an increase in childhood obesity prevalence by 0.640 (95%CI: 0.515-0.765), 0.972 (95%CI: 0.819-1.126), 1.676 (95%CI: 1.475-1.877), and 2.373 (95%CI: 2.135-2.612) percentage points, respectively. Compared to girls and non-Hispanic whites and Asians, the impact of COVID-19 on childhood obesity was modestly larger among boys and non-Hispanic blacks and Hispanics, respectively.

CONCLUSION

Public health interventions are urgently called to promote an active lifestyle and engagement in physical activity among children to mitigate the adverse impact of COVID-19 on unhealthy weight gains and childhood obesity.

Does exercising before or after a meal affect energy balance in adolescents with obesity?

BACKGROUND AND AIM

Exercise timing has been suggested to affect appetite and energy intake (EI). The aim of this study was to examine the impact of exercising immediately before or after a meal on EI, appetite sensations and food reward (FR) in adolescents with obesity.

METHODS AND RESULTS

Seventeen adolescents with obesity completed 3 experimental sessions (randomized controlled trial): rest + lunch (CON); exercise + lunch (EX-MEAL); lunch + exercise (MEAL-EX). The exercise consisted of cycling 30 min at 65%V̇O_2peak. Outcomes included ad libitum EI (weighed lunch and dinner), FR (Leeds Food Preference Questionnaire at pre- and post-combination of exercise/rest and lunch, and pre-dinner) and appetite sensations (visual analogue scales). EI was not different between conditions. Compared with CON, relative EI at lunch was lower in EX-MEAL and MEAL-EX (p ≤ 0.05) and daily only in MEAL-EX (p < 0.01). Postprandial fullness was higher in EX-MEAL compared to CON. Compared with CON, both EX-MEAL and MEAL-EX attenuated the increase in wanting for sweet food and reduced explicit liking for fat.

CONCLUSIONS

These preliminary results suggest that exercising immediately before or after a meal produce few differences in appetite and have small beneficial effects on overall energy balance in adolescents with obesity, as well as on FR.

CLINICAL TRIALS

NCT03967782.

A review of the short- and long-term impact of weight loss on appetite in youth: what do we know and where to from here?

This review seeks to synthesise our knowledge about changes in hunger and satiety that occur during diet-induced weight loss and during weight loss maintenance, with a particular focus on youth with obesity. Mechanisms of appetite responses to weight loss rely heavily on the adult literature. Physiological mechanisms that control appetite and satiety via the gut-brain axis have been elucidated but we have an incomplete picture of changes in gut hormones and peptides in youth with obesity. In adolescents, the role of the brain in long-term sensing of body composition and modifying appetite and satiety changes is easily over-ridden by hedonic influences for the reward of highly palatable sweet foods and encourages over-consumption. Accordingly, reward cues and hyper-responsiveness to palatable foods lead to a pattern of food choices. Different reward systems are necessary that are substantial enough to reward the continued individual effort required to sustain new behaviours, that need to be adopted to support a reduced body weight. Periods of growth and development during childhood provide windows of opportunity for interventions to influence body weight trajectory but long-term studies are lacking. More emphasis needs to be placed on anticipatory guidance on how to manage powerful hedonic influences of food choice, essential to cope with living in our obesogenic environment and managing hunger which comes with the stronger desire to eat after weight has been lost.

Appetite control and exercise: Does the timing of exercise play a role?

The prevention and management of chronic diseases, particularly overweight and obesity, relies on multidisciplinary strategies mainly combining dietary approaches with physical activity. Recently, the timing of exercise (time of the day as well as delay/position relative to a meal) has been suggested as an important parameter to consider when prescribing physical activity. Some studies have for instance shown the interest of the timing of exercise on the glycemia, sleep and body composition regulation. However, the impact of exercise-timing on appetite control and energy intake remains unclear. This is why, the present paper questions whether physical exercise, depending on its timing during the day and related to a meal, can affect energy intake, appetite sensations and food reward. Although evidences remain actually limited, exercising during the morning; and particularly close to lunch, might have a better impact on overall energy balance through reduced subsequent energy intake, without leading to compensatory intakes at the following meals. Importantly, dealing with the timing of exercise to optimize energy balance (and affect energy intake and appetite) does not only require to consider its time during the day (morning vs. afternoon or evening), but also and maybe mainly its order/position (pre vs. post) and delay regarding meals. While the actual literature remains limited in this area, the present paper tends to highlight the importance of considering the timing of exercise to optimize our impact on the overall energy balance, and to encourage the elaboration of further studies to better understand and determine the potential effect of this timing of exercise, in order to find the best combination between the different exercise characteristics, intensity, duration, modality, to empower these effects.

Associations between Physical Activity and Food Intake among Children and Adolescents: Results of KiGGS Wave 2

A balanced diet and sufficient physical activity are essential for the healthy growth of children and adolescents and for obesity prevention. Data from the second wave of the population-based German Health Interview and Examination Survey for Children and Adolescents (KiGGS Wave 2; 2014-2017) were used to analyse the association between food intake and physical activity among 6- to 17-year-old children and adolescents (n = 9842). Physical exercise (PE) and recommended daily physical activity (RDPA) were assessed with self-administered questionnaires and food intake by a semi-quantitative food frequency questionnaire. Multivariable logistic regression was used to analyse the association between food group intake (dependent variable) and level of PE or RDPA. High levels of physical activity (PE or RDPA) were associated with higher consumption of juice, water, milk, dairy products, fruits, and vegetables among both boys and girls, and among boys with a higher intake of bread, potatoes/pasta/rice, meat, and cereals. Higher PE levels were also less likely to be associated with a high soft drink intake. High levels of RDPA were associated with high intake of energy-dense foods among boys, which was not observed for PE. This study indicates that school-aged children and adolescents with higher levels of physical activity consume more beneficial foods and beverages compared to those with lower physical activity levels.

Brain reactivity to visual food stimuli after moderate-intensity exercise in children

Exercise may play a role in moderating eating behaviors. The purpose of this study was to examine the effect of an acute bout of exercise on neural responses to visual food stimuli in children ages 8-11 years. We hypothesized that acute exercise would result in reduced activity in reward areas of the brain. Using a randomized cross-over design, 26 healthy weight children completed two separate laboratory conditions (exercise; sedentary). During the exercise condition, each participant completed a 30-min bout of exercise at moderate-intensity (~ 67% HR maximum) on a motor-driven treadmill. During the sedentary session, participants sat continuously for 30 min. Neural responses to high- and low-calorie pictures of food were determined immediately following each condition using functional magnetic resonance imaging. There was a significant exercise condition*stimulus-type (high- vs. low-calorie pictures) interaction in the left hippocampus and right medial temporal lobe (p < 0.05). Main effects of exercise condition were observed in the left posterior central gyrus (reduced activation after exercise) (p < 0.05) and the right anterior insula (greater activation after exercise) (p < 0.05). The left hippocampus, right medial temporal lobe, left posterior central gyrus, and right anterior insula appear to be activated by visual food stimuli differently following an acute bout of exercise compared to a non-exercise sedentary session in 8-11 year-old children. Specifically, an acute bout of exercise results in greater activation to high-calorie and reduced activation to low-calorie pictures of food in both the left hippocampus and right medial temporal lobe. This study shows that response to external food cues can be altered by exercise and understanding this mechanism will inform the development of future interventions aimed at altering energy intake in children.

Protein Intake Estimated from Brief-Type Self-Administered Diet History Questionnaire and Urinary Urea Nitrogen Level in Adolescents

Our aim was to assess the validity of the brief-type self-administered diet history questionnaire (BDHQ15y) to estimate the protein intake in 248 Japanese secondary school students (mean age = 14.2 years), using urinary biomarkers as references. Participants provided three samples of overnight urine for measurement of urea nitrogen and creatinine levels, underwent anthropometric measurements, and answered the questionnaires. Additionally, 58 students provided 24-h urine specimens. A significant correlation was observed between excretion of urea nitrogen in overnight and 24-h urine specimens (ρ = 0.527; p < 0.001), with biases ≤5.8%. The mean daily protein intake estimated from urinary biomarkers was 76.4 ± 20.4 g/d in males and 65.4 ± 16.9 g/d in females, and the mean protein intake estimated from the BDHQ15y (PRTbdhq) was 89.3 ± 33.7 g/d in males and 79.6 ± 24.6 g/d in females. Crude and energy-adjusted coefficients of correlation between PRTbdhq and protein intake estimated from urinary biomarkers were 0.205 (p = 0.001; 0.247 for males and 0.124 for females), and 0.204 (p = 0.001; 0.302 for males and 0.109 for females), respectively. The BDHQ15y is a low-cost tool to assess protein intake of a large population, instead of a weakness of overestimation.

Effect of Exercise Duration on Subsequent Appetite and Energy Intake in Obese Adolescent Girls

There is a growing interest regarding the effect of exercise on appetite and energy intake in youth. While the role of exercise intensity has been a primary focus of study, the effect of exercise duration on subsequent food intake has not been fully examined in obese adolescents. On three separate mornings in a randomly assigned order, obese adolescent girls (n = 20) aged 12-15 years old were asked to perform a rest session (control, CON) or two cycling sessions for 20 (EX20) or 40 min (EX40) set at their ventilatory threshold. Absolute and relative energy intake were measured from an ad libitum lunch meal 30 min after rest or exercise and appetite feelings assessed using visual analogue scales throughout the day. Hunger, satiety, and prospective food consumption were not significantly different between conditions. Absolute energy intake (kcal) did not differ between conditions, while relative energy intake on EX40 (571 ± 381 kcal) was significantly lower than during CON (702 ± 320 kcal; p < .05) and EX20 (736 ± 457 kcal; p < .05). Fat ingestion (in grams) was significantly lower on CON (7.8 ± 3.2 g) compared with EX20 (10.3 ± 4.6 g; p < .01). Protein intake (in grams) was higher on EX20 (37.0 ± 16.6 g) compared with both CON (29.5 ± 11.7 g; p < .01) and EX40 (33.1 ± 10.9 g; p < .05). However, the percentage of total energy derived from each macronutrient was not different between conditions. Obese adolescent girls do not compensate for an acute bout of exercise set at their ventilatory threshold by increasing energy intake, regardless of the exercise duration.

Energy depletion by 24-h fast leads to compensatory appetite responses compared with matched energy depletion by exercise in healthy young males

Although there is a growing interest for the effects of intermittent fasting on energy balance, this study aimed to compare appetite, energy intake and food reward responses with an energy depletion induced either by 24-h food restriction or an equivalent deficit with exercise in healthy males. In all, twelve healthy lean males (21·5 (sd 0·5) years old; BMI: 22·5 (sd 1·7) kg/m2) participated in this study. Body composition, aerobic capacity, food preferences and energy intake were assessed. They randomly completed three conditions: (i) no depletion (CON); (ii) full 24-h energy restrictions (Def-EI); and (iii) exercise condition (Def-EX). Ad libitum energy intake and food reward were assessed at the end of each session. Appetite feelings were assessed regularly. Ad libitum energy intake was higher on Def-EI (7330 (sd 2975) kJ (1752 (sd 711) kcal) compared with that on CON (5301 (sd 1205) kJ (1267 (sd 288) kcal)) (P<0·05), with no difference between CON and Def-EX (6238 (sd 1741) kJ (1491 (sd 416) kcal) (P=0·38) and between Def-EX and Def-EI (P=0·22). There was no difference in the percent energy ingested from macronutrients. Hunger was lower on CON and Def-EX compared with Def-EI (P<0·001). Satiety was higher on CON and Def-EI compared with that on Def-EX (P<0·001). There was a significant interaction condition × time for food choice fat bias (P=0·04), showing a greater preference for high-fat v. low-fat food during Def-EI and Def-EX. Although 24-h fasting leads to increased energy intake at the following test meal (without total daily energy intake difference), increased hunger profile and decreased post-meal food choice fat bias, such nutritional responses are not observed after a similar deficit induced by exercise.

Benefits of different intensity of aerobic exercise in modulating body composition among obese young adults: a pilot randomized controlled trial

BACKGROUND

The aim of present study was to compare the effects of different aerobic exercise intensities and energy expenditures on the body composition of sedentary obese college students in Taiwan.

METHODS

Forty-eight obese participants [body mass index (BMI) ≥ 27 kg/m², age 18-26 years] were randomized into four equal groups (n = 12): light-intensity training group (LITG), 40%-50% heart rate reserve (HRR); middle-intensity training group (MITG), 50%-70% HRR; high-intensity training group (HITG), 70%-80% HRR; and control group (CG). The aerobic exercise training program was conducted for 60 min per day on a treadmill 3 days per week for 12 weeks. All participant anthropometric data, blood biochemical parameters, and health-related physical fitness components were measured at baseline and after 12 weeks.

RESULTS

At baseline, the anthropometric indices did not differ significantly among the four groups (p > 0.05). After 12-week exercise intervention, the HITG and MITG had significantly more changes in body weight, waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) than the LITG. The changes in BMI and body fat percentage differed among all four groups (p < 0.05).

CONCLUSIONS

A 12-week high-intensity exercise intervention with high energy expenditure can considerably reduce body weight, body fat, WC, WHR, and WHtR, whereas a light-intensity exercise intervention can significantly reduce body weight and body fat.

TRIAL REGISTRATION

Current Controlled Trials TPECTR09831410900 , registered on 24^th Dec 2009.

A systematic review and meta-analysis of energy and macronutrient intake responses to physical activity interventions in children and adolescents with obesity

BACKGROUND

The effects of regular physical activity on energy intake in obese adolescents are unknown.

OBJECTIVE

The objective is to determine how physical activity interventions affect energy and macronutrient intake in overweight/obese youth.

DATA SOURCES

Databases were searched from December 2014 to December 2015 for studies that measured energy and/or macronutrient consumption in response to physical activity intervention in overweight/obese youth.

DATA SELECTION

The review comprises primary source articles published in English in peer-reviewed journals. Articles that presented data on energy and/or macronutrient intake before and after a physical activity intervention (without dietary restriction) in overweight or obese children and teenagers (up to 18 years old) were included. Of the initial 307 references found, nine were included.

RESULTS

The nine included studies analysed the effect of 15 different physical activity interventions. Nine showed a decrease and six unchanged energy intakes. The effect size for total energy intake ranged from -2.108 to -0.207 (n = 14). Results of the meta-analysis revealed a mean effect of physical intervention to reduce intake of -1.003 (95% confidence interval = -1.261 to -0.745, p < 0.001). Results for heterogeneity among these studies were I²  = 67.421; Q = 39.903; d_f  = 13, p < 0.001. The mean energy intake reduction was -323 ± 286 kcal. Macronutrient intake was assessed in 11 interventions. Protein intake was found decreased in five (reduction of -26.8 ± 19.2 g), seven reported fat decrease (reduction of -26.4 ± 17.8 g) and five a decrease in CHO (reduction of -72.5 ± 22.8 g). The meta-analysis revealed significant decreases of each macronutrient (p < 0.001).

CONCLUSION

Structured physical activity interventions favour decreased daily energy intake in obese adolescents.

Acute post-exercise energy and macronutrient intake in lean and obese youth: a systematic review and meta-analysis

AIM

This review aims to determine if acute exercise affects subsequent energy and macronutrients intake in obese and non-obese children and adolescents.

METHODS

Databases were searched between January 2015 and December 2015 for studies reporting energy and/or macronutrients intake immediately after an acute exercise and control condition, in children and adolescents. From the initial 118 references found, 14 were included for subsequent analysis after screening representing 31 acute exercise conditions that varied in intensity, duration and modality.

RESULTS

One study found increased energy intake after exercise, seven decreased and 23 revealed no change. The meta-analysis revealed a significant effect of acute exercise on intake in obese but not in lean youth by a mean difference of -0.430 (95% confidence interval=-0.703 to -0.157, P=0.002) displaying low heterogeneity (I²=0.000; Q=5.875; d_f=9, P=0.752). The analysis showed that intense exercise only reduces intake in obese children (no intensity effect in lean). Unchanged macronutrients intake was reported in nine studies as opposed to three which found modified lipids, protein and/or carbohydrate intake.

CONCLUSION

Although acute exercise does not affect energy intake in lean, it appears to reduced food intake in obese youth when intense, without altering the macronutrients composition of the meal.

Body composition and energy intake - skeletal muscle mass is the strongest predictor of food intake in obese adolescents: The HEARTY trial

There has been renewed interest in examining the relationship between specific components of energy expenditure and the overall influence on energy intake (EI). The purpose of this cross-sectional analysis was to determine the strongest metabolic and anthropometric predictors of EI. It was hypothesized that resting metabolic rate (RMR) and skeletal muscle mass would be the strongest predictors of EI in a sample of overweight and obese adolescents. 304 post-pubertal adolescents (91 boys, 213 girls) aged 16.1 (±1.4) years with body mass index at or above the 95th percentile for age and sex OR at or above the 85th percentile plus an additional diabetes risk factor were measured for body weight, RMR (kcal/day) by indirect calorimetry, body composition by magnetic resonance imaging (fat free mass (FFM), skeletal muscle mass, fat mass (FM), and percentage body fat), and EI (kcal/day) using 3 day food records. Body weight, RMR, FFM, skeletal muscle mass, and FM were all significantly correlated with EI (p < 0.005). After adjusting the model for age, sex, height, and physical activity, only FFM (β = 21.9, p = 0.007) and skeletal muscle mass (β = 25.8, p = 0.02) remained as significant predictors of EI. FFM and skeletal muscle mass also predicted dietary protein and fat intake (p < 0.05), but not carbohydrate intake. In conclusion, with skeletal muscle mass being the best predictor of EI, our results support the hypothesis that the magnitude of the body's lean tissue is related to absolute levels of EI in a sample of inactive adolescents with obesity.

The effects of a mid-morning snack and moderate-intensity exercise on acute appetite and energy intake in 12-14-year-old adolescents

Energy intake (EI) and energy expenditure (EE) should not be considered independent entities, but more an inter-connected system. With increased physical activity and reduced snacking initiatives as prevalent Public Health measures, any changes to subsequent EI from these recommendations should be monitored. The aim of this study was to investigate changes in acute EI and appetite over four conditions: (1) a control condition with no snack and no exercise (CON); (2) a snack condition (+1 MJ; SK); (3) a moderate-intensity cycling exercise condition (-1 MJ; EX); and finally (4) both snack and exercise condition (+1 MJ, -1 MJ; EXSK). Acute changes in appetite (visual analogue scale) and lunchtime EI (ad libitum pizza meal) were recorded in twenty boys and eighteen girls (12-13 years). Lunch EI was not significantly different between conditions or sexes (P>0·05). Relative EI was calculated, where the energy manipulation (+1 MJ from the snack or -1 MJ from the exercise) was added to lunchtime EI. Relative EI indicated no significant differences between the sexes (P>0·05); however, in the EX condition, relative EI was significantly lower (P<0·001) compared with all other conditions. Appetite increased significantly over time (P<0·001) and was significantly higher in the CON and EX conditions compared with the SK and EXSK conditions. No significant sex differences were found between conditions. When aiming to evoke an acute energy deficit, increasing EE created a significantly larger relative energy deficit than the removal of the mid-morning snack. Sex was not a confounder to influence EI or appetite between any of the conditions.

Active video games and energy balance in male adolescents: a randomized crossover trial

BACKGROUND

Active video games (AVGs) have been shown to acutely increase energy expenditure when compared with seated video games; however, the influence of AVGs on compensatory adjustments in energy intake and expenditure is largely unknown.

OBJECTIVE

The aim was to examine the acute effects of AVGs on energy intake and expenditure.

DESIGN

With the use of a randomized crossover design, 26 male adolescents (mean ± SD age: 14.5 ± 1.4 y) completed three 1-h experimental conditions: resting control, seated video game play (Xbox 360; Microsoft), and AVG play (Kinect Adventures on Xbox 360) followed by an ad libitum lunch. A validated food menu was used to assess food intake immediately after the conditions and for the remainder of the day, and a dietary record was used for the subsequent 3-d period. Energy expenditure was measured by using portable indirect calorimetry throughout each experimental condition, and an accelerometer was used to assess the subsequent 3-d period. Appetite sensations were assessed by using visual analog scales at different time points during the testing day. The primary outcomes were acute (immediately after the conditions and 24-h) and short-term (3-d) energy intake and expenditure.

RESULTS

Energy expenditure was significantly higher (~145%; P < 0.001) during the AVG condition than during the resting control and seated video game conditions; however, no significant differences in energy expenditure were observed 24 h (~6%; P > 0.49) and 3 d after the experimental conditions (~3%; P > 0.82). No significant differences were observed in absolute energy intake immediately after the conditions (~2%; P > 0.94) or in absolute energy intake 24 h (~5%; P > 0.63) and 3 d (~9%; P > 0.53) after the experimental conditions. Finally, appetite sensations were similar between conditions at all time points (P > 0.05).

CONCLUSIONS

The increase in energy expenditure promoted by a single session of Kinect AVG play is not associated with increased food intake but is compensated for after the intervention, resulting in no measurable change in energy balance after 24 h. These results suggest that the potential of Kinect to reduce the energy gap underlying weight gain is offset within 24 h in male adolescents. This trial was registered at clinicaltrials.gov as NCT01655901.

Nutritional responses to acute training sessions in young elite rugby players

BACKGROUND

Acute exercise has been shown to induce nutritional adaptations in obese and lean inactive youth but it remains unclear whether youth with a high level of physical activity experience such exercise-induced energy intake and appetite modifications.

METHODS

14 (15- to 16-year-old) male elite rugby players completed sessions on three separate occasions: (1) a control session (CON); (2) an exercise session (EX) and; (3) a rugby session (RUGBY). The energy induced by the rugby and exercise sessions was matched (Polar Team2 pro technology), and participants' energy intake, food preferences (ad libitum buffet meals) and appetite feelings (Visual Analogue Scales) were assessed throughout the experimental days.

RESULTS

The energy intake during lunch and snack time was not different between conditions. Dinner time energy intake was significantly increased after RUBGY compared to CON with respectively 969 ± 145 kcal and 777 ± 183 kcal (p < 0.05). The energy intake at dinner time was significantly increased during EX (1185 ± 199 kcal) compared to both CON (p < 0.001) and RUGBY (p < 0.01). None of the appetite feelings investigated were modified between sessions.

CONCLUSION

Adolescent elite rugby players regulate their energy intake differently depending on the nature of their training; independently of the energy expended. This demonstrates the need for energetic and nutritional education to optimize their physical fitness and performance.

Shifts in the recent distribution of energy intake among U.S. children aged 2-18 years reflect potential abatement of earlier declining trends

Recent national surveys suggest that child obesity in the United States may have reached a plateau, but corresponding trends in energy intake have not been examined in depth. This article evaluates medium-term trends in children's reported energy intake by using 4 waves of national dietary surveillance from 2003-2004 to 2009-2010. The analysis uses up to 2 24-h dietary recalls, incorporating methods that address challenges in estimating usual intake, accounting for intraindividual variance and covariates such as the presence of atypical consumption days. Quantile regression was used to assess disparities in intake among sociodemographic subgroups at extremes of the distribution as well as at the median, and the potential influence of misreporting was evaluated. Results indicated that after an initial decline in intakes across all age groups through 2007-2008, there were significant increases of ∼90 kcal/d at the median among adolescents in 2009-2010, whereas intakes in younger children remained steady. Among adolescent boys, the recent increase was larger at the 90th percentile than at the median. Intake trends did not vary by race/ethnic group, among whom intakes were similar at the upper end of the distribution. Misreporting did not influence trends over time, but intakes were lower in younger children and higher in older children after excluding misreporters. Overall, findings suggest that declines in children's energy intake from 2003-2004 through 2007-2008 were consistent with the obesity plateau observed in most age and gender subgroups through 2009-2010. However, there is evidence of increased intakes among adolescents in 2009-2010, which may threaten the earlier abatement in overweight in this older age group.

Sedentary behaviour as an emerging risk factor for cardiometabolic diseases in children and youth

Sedentary behaviour (e.g. TV viewing, seated video game playing, prolonged sitting) has recently emerged as a distinct risk factor for cardiometabolic diseases in children and youth. This narrative review provides an overview of recent evidence in this area and highlights research gaps. Current evidence suggests that North American children and youth spend between 40% and 60% of their waking hours engaging in sedentary pursuits. Although data are lacking concerning temporal trends of objectively measured sedentary time, self-reported sedentary behaviours have increased over the past half century, with a rapid increase since the late 1990s. Excessive sedentary behaviour has been found to have independent and deleterious associations with markers of adiposity and cardiometabolic disease risk. These associations are especially consistent for screen-based sedentary behaviours (TV viewing, computer games, etc), with more conflicting findings observed for overall sedentary time. The above associations are possibly mediated by the influence of screen-based sedentary behaviours on energy intake. Although excessive sitting has been reported to have adverse acute and chronic metabolic impacts in adults, research on children is lacking. Research is particularly needed to investigate the impact of characteristics of sedentary behaviour (i.e. type/context, sedentary bout length, breaks in sedentary time, etc), as well as interventions that examine the health and behavioural impacts of sitting per se.

Is there spontaneous energy expenditure compensation in response to intensive exercise in obese youth?

BACKGROUND

Physical activity is mainly used in weight control strategies to favour energy expenditure. Some evidence suggests that exercise might not have the expected impact on energy balance, and may actually cause a decrease in the subsequent physical activity energy expenditure.

OBJECTIVE

To question the impact of an acute exercise session of varying intensities on daily energy expenditure in lean and obese adolescents.

METHODS

Data from three separate studies conducted in lean and obese 12-15 years old adolescents (study 1: 12 obese; study 2: 10 obese and nine lean; study 3: 15 obese) have been used. Daily energy expenditure (DEE) was assessed in studies 1 and 2 during an exercise condition with an exercise bout at 70%VO(2max) (EX) and a rest day (REST) (using Actiheart and Armbands, respectively). In study 3, DEE was assessed in calorimetric chambers during (i) a high intensity exercise condition (HIE - 75%VO(2max)) and (ji) a condition with a low intensity exercise (LIE - 40%VO(2max)) and (iii) a rest condition (REST).

RESULTS

Morning energy expenditure was significantly higher during the exercise conditions whatever the intensity compared with rest. Afternoon energy expenditure was significantly lower following HIE compared to the rest condition in studies 2 and 3. Afternoon energy expenditure was not significantly different between LIE and REST in study 2. Total DEE was not significantly different between conditions in the three studies.

CONCLUSION

Obese adolescents seem to show a compensatory response to an acute session of HIE (>70%VO(2max)) by decreasing their following physical activity energy expenditure. Although HIE favours body composition, physical fitness and metabolic profile improvements, this induced compensatory energy expenditure response has to be considered to optimize its effect on weight loss.

Daily physical activity patterns of children with delayed eating behaviors

Night eating syndrome (NES) is a delayed pattern of energy intake. It is unknown if symptoms associated with this syndrome are accompanied by a delayed pattern of physical activity. This study examines the relationship between physical activity patterns and delayed eating behaviors in children. Children from the QUALITY cohort (n = 269, 45% female, aged 8-11 y) completed the Night Eating Questionnaire (NEQ), which measures NES symptoms on a continuous scale and identifies single NES symptoms. Daily accelerometer data were transformed into mean counts per wear-time minute for each hour of the day. Children with high NEQ scores had higher levels of daily (p < 0.001) and evening physical activity (p = 0.05) and reached 75% of their total daily physical activity 20 minutes later than children with low NEQ scores (p < 0.05). Excessive evening snacking and a strong urge to eat in the evening or at night were the symptoms most related to these physical activity patterns. Children with delayed eating behaviors had higher levels of physical activity in the late morning and evening and a delayed physical activity pattern compared to children with no or fewer symptoms. Future research is needed to determine if physical activity plays a role in the onset or maintenance of night eating.

Obese but not lean adolescents spontaneously decrease energy intake after intensive exercise

BACKGROUND

Acute intensive exercise has been shown to induce a decreased subsequent daily energy intake in obese adolescents without altering the subjective appetite feelings. It is however unclear whether or not those nutritional adaptations to acute exercise are affected by the adolescents' weight status. The aim of this study was to compare the energy intake and macronutrient preferences, appetite feeling and energy expenditure response to acute exercise between lean and obese adolescents.

METHODS

Ten obese and nine normal weight 12-15year old adolescents randomly completed a session with a 30minute cycling exercise at 75% VO2max and a sedentary session. During both sessions energy expenditure was assessed using Armband, ad libitum energy intake measured by weighing at both lunch and dinner time and appetite feelings assessed using visual analog scales.

RESULTS

Daily, morning and afternoon energy expenditure were significantly higher in obese than in normal weight adolescents (p<0.001). Total energy expenditure was significantly higher during EX (1086±157kcal) compared to SED (853±154kcal) in lean (p<0.05) but not significantly different in obese (respectively 1865±222 and 1803±232kcal). Afternoon energy expenditure was significantly lower during EX compare to SED in obese (p<0.05) but not in normal weight adolescents. Lunch, dinner and total daily energy intake were significantly reduced after the exercise session in obese (p>0.05) but not in lean adolescents. No group or condition effects were observed on subjective appetite feelings.

DISCUSSION

Post exercise spontaneous energy intake and energy expenditure are reduced in obese but not in normal weight adolescents, without appetite feeling changes. Acute exercise may have a greater impact on energy balance through the induced decreased energy intake in the absence of significant change in energy expenditure in obese youth.

Prolonged sitting and markers of cardiometabolic disease risk in children and youth: a randomized crossover study

OBJECTIVE

Recent evidence suggests that short bouts of uninterrupted sedentary behavior reduce insulin sensitivity and glucose tolerance while increasing triglyceride levels in both healthy and overweight/obese adults. To date no study has examined the acute impact of uninterrupted sitting in children and youth. The objective of the present study was to determine whether 8 h of uninterrupted sitting increases markers of cardiometabolic disease risk in healthy children and youth, in comparison to 8 h of sitting interrupted by light intensity walk breaks or structured physical activity.

MATERIALS/METHODS

11 healthy males and 8 healthy females between the ages of 10 and 14 years experienced 3 conditions in random order: (1) 8 h of uninterrupted sitting (Sedentary); (2) 8 h of sitting interrupted with a 2-min light-intensity walk break every 20 min (Breaks); and (3) 8 h of sitting interrupted with a 2-min light-intensity walk break every 20 min as well as 2×20 min of moderate-intensity physical activity (Breaks+Physical Activity). Insulin, glucose, triglyceride, HDL and LDL cholesterol area under the curve were calculated for each condition.

RESULTS

We observed no significant differences in the area under the curve for any marker of cardiometabolic disease risk across the 3 study conditions (all p>0.09).

CONCLUSIONS

These results suggest that in comparison to interrupted sitting or structured physical activity, a single bout of 8 h of uninterrupted sitting does not result in measurable changes in circulating levels of insulin, glucose, or lipids in healthy children and youth.

Children and youth do not compensate for an imposed bout of prolonged sitting by reducing subsequent food intake or increasing physical activity levels: a randomised cross-over study

The behavioural impact of an imposed bout of prolonged sitting is yet to be investigated in the paediatric population. The objective of the present study was to determine the acute effect of prolonged sitting onad libitumfood intake and spontaneous physical activity (PA) levels in healthy children and youth. A total of twenty healthy youth (twelve males and eight females) aged 10–14 years, with a mean BMI of 18·6 (sd4·3) kg/m2, were exposed to three experimental conditions in a random order: (1) a day of uninterrupted sitting (Sedentary); (2) a day of sitting interrupted with a 2 min light-intensity walk break every 20 min (Breaks); (3) a day of sitting interrupted with a 2 min light-intensity walk break every 20 min as well as 2 × 20 min of moderate-intensity PA (Breaks+PA). Food intake (ad libitumbuffet meal) and PA (accelerometry for 24 h) were assessed following exposure to each experimental condition. Despite significant differences in sedentary behaviour and activity levels during the three in-laboratory sessions (allP< 0·01), we did not observe any differences inad libitumfood intake immediately following exposure to each experimental condition or any changes in the levels of sedentary behaviour or PA in the 24 h following exposure to each experimental condition (allP>0·25). These findings suggest that children and youth may not compensate for an imposed bout of sedentary behaviour by reducing subsequent food intake or increasing PA levels.