Effect of exercise-meal timing on energy intake, appetite and food reward in adolescents with obesity: The TIMEX study

The Role of Meal Timing in Appetitive Responses to Acute Exercise in Adolescents with and without Obesity: A Systematic Review and Meta-Analysis

Physical activity has been shown to improve various aspects of metabolic health and is frequently applied as an intervention in the management and prevention of overweight/obesity. Chrono-exercise can be studied in relation to time of day and timing in relation to a meal, which encompasses chronology and duration of the temporal interval, but the latter has received limited attention to date. This brief review and meta-analysis investigates whether the timing of a meal subsequent to acute exercise in children and adolescents with and without overweight/obesity moderates eating behavior and appetite. A quantitative synthesis of 28 controlled trials with 51 distinct conditions (N = 575; median sample size = 15, median age = 13 y, n = 297 overweight/obesity) was performed using multilevel random-effects meta-regressions and restricted splines to test the linear and nonlinear relationships between mean differences in energy intake between exercise and control conditions and the duration of the exercise-test meal interval, and if this moderated by participant weight status or exercise characteristics (i.e., intensity, duration, and method). Commencement of meals occurred from immediately to 3 h after cessation of exercise (median = 30 min, interquartile range = 8 min). The meal interval was not associated with effect sizes overall in the linear and spline analysis (ps = 0.576 and 0.971, respectively). Although there was only an interaction with weight status present in the linear analysis (P < 0.001), the meal interval significantly moderated effect sizes within-study arms with lean participants (ps = 0.006 and 0.019, respectively), but not in those with overweight/obesity (ps = 0.070 and 0.620, respectively) in both analyses. Exercise characteristics did not have an impact on this relationship. Taken together, prescriptions for meal timing may depend on the individual phenotype when seeking to optimize potential anorexigenic effects of acute exercise. This trial was registered at PROSPERO as CRD42021287838. (https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=287838).

Lifestyle-Related Factors for Improving Diet Quality

Background/Objectives: Diet quality is important for the prevention of non-communicable diseases (NCDs), which are now responsible for leading causes of death worldwide. Although health professionals often recommend diet improvement for the treatment and management of many NCDs, patients continually struggle to make dietary changes and maintain them long-term. This may be due to an interplay of many factors that affect dietary quality. This paper discusses some lifestyle-related factors that may offer additional points of intervention for health professionals to use to increase diet quality. Methods: This review examines the effects of exercise, sleep, mindfulness practice, meal socialization, social media use, and tobacco and alcohol use on diet quality. Studies examining the effects of these factors on diet were found by searching PubMed, CINAHL, and Google Scholar. Results: Evidence suggests that a positive relationship between exercise, adequate sleep, and all forms of mindfulness have positive effects on diet quality. Meal socialization's effects on diet quality were nuanced. Individuals tend to eat similarly to those they share a meal with. However, food quantity intake may be affected by the physical characteristics of individuals with whom people share a meal. Social media use was found to have negative effects on diet quality in those who used it excessively and was found to promote disordered eating patterns. Both tobacco and alcohol use were found to have negative impacts on diet quality. Conclusions: Using these findings, health professionals may be able to educate people about lifestyle-related factors that can improve diet quality.

The impact of exercise timing on energy intake: A systematic review and meta-analysis of diurnal and meal timing effects

This systematic review and meta-analysis examine the literature (up to August 2nd, 2024) on the influence of exercise timing on energy intake in both children and adults. A comprehensive search was conducted using MEDLINE, EMBASE, Cochrane Library, SPORTDiscus, and Web of Science Core Collection, following PRISMA guidelines. The review was registered in Prospero (CRD42024553381) and evaluated using QUADAS-2. From an initial 3276 articles, a meta-analysis (six studies) revealed that daily energy intake was not significantly lower when exercise was performed in the morning versus the afternoon/evening: mean difference of 64 ± 77 kcal (95% CI: 86 to 215 kcal; p = 0.403). A meta-analysis (three studies, all with children) comparing lunch energy intake before versus after exercise showed a significant difference in energy intake when exercise was performed post-meal: (-39 ± 13 kcal, 95% CI: 63 to -14 kcal; p = 0.002). For the meta-analysis of delayed lunch (five studies), where exercise ended 15 min to 4 h before the meal, and the delay between the start of each exercise condition within the same study was typically around 2 h, no significant difference in energy intake was found (-2±67 kcal; 95% CI: 134 to 130 kcal; p = 0.977). Regarding chronic exercise, a decrease in energy intake was observed with evening exercise (one study), morning exercise (two studies) or independently of exercise timing (two studies). In conclusion, findings suggest acute exercise may reduce intake in children and adolescents, but this effect is dependent on the timing of exercise.

The effects of acute exercise on food intake and appetite in adolescents with and without obesity: A systematic review and meta-analysis

This systematic review and meta-analysis synthesized evidence pertaining to consummatory and appetitive responses to acute exercise in children and adolescents with and without obesity (5-18 years). Articles reporting on supervised, controlled trials of any modality, duration, or intensity with laboratory-measured food intake were found using MEDLINE, EMBASE, and Cochrane up to July 2023. Differences between conditions in laboratory energy and macronutrient intake, appetite sensations, and food reward were quantitatively synthesized using random-effects meta-analyses. Thirty-five studies were eligible for the systematic review of energy intake, consisting of 60 distinct intervention arms with lean (n = 374) and overweight/obesity participants (n = 325; k = 51 eligible for meta-analysis). Study quality as indicated by the Effective Public Healthy Practice Project tool was rated as low and moderate risk of bias for 80% and 20% of studies, respectively. Acute exercise had no significant effect on energy intake during an ad libitum test meal (mean difference [MD] = -4.52 [-30.58, 21.54] kcal, p = .729). Whilst absolute carbohydrate intake was lower after exercise (23 arms; MD = -6.08 [-11.26, -0.91] g, p = .023), the proportion of carbohydrate was not (30 arms; MD = -0.62 [-3.36, 2.12] %, p = .647). A small elevation in hunger (27 arms; MD = 4.56 [0.75, 8.37] mm, p = .021) and prospective food consumption (27 arms; PFC; MD = 5.71 [1.62, 9.80] mm, p = .008) was observed post-exercise, but not immediately prior to the test meal (Interval: Mdn = 30 min, Range = 0-180). Conversely, a modest decrease in explicit wanting for high-fat foods was evident after exercise (10 arms; MD = -2.22 [-3.96, -0.47] mm, p = .019). Exercise intensity (p = .033) and duration (p = .013) moderated food intake only in youth with overweight/obesity, indicating lower intake at high intensity and short duration. Overall, acute exercise does not lead to compensation of energy intake or a meaningful elevation of appetite or food reward and might have a modest benefit in youth with overweight/obesity if sufficiently intense. However, conclusions are limited by substantial methodological heterogeneity and the small number of trials employing high-intensity exercise, especially in youth with overweight/obesity.

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.

The energy content of meals with a similar macronutrient distribution may have a greater impact on appetite sensations than food preferences in adolescents with obesity: A secondary analysis

PURPOSE

The energy and macronutrient composition of a meal has been shown to influence postprandial appetitive responses, but it is not clear how energy content independent of macronutrient distribution affects postprandial appetite in adolescents with obesity. Extracting data from a primary study testing the effect of energy turnover on appetite, this secondary analysis assessed how fixed meals varying in energy content with similar macronutrient distributions influences postprandial appetite sensations and food reward.

METHODS

Using a randomised, counterbalanced crossover design, N = 14 adolescents with obesity (Mage = 12.71, SDage = 0.99; 10 female) consumed fixed lunch meals with similar macronutrient content starting at 750 kcal in energy and progressively increasing by 250 kcal on three different test days. Liking and wanting for food images varying in fat and taste were assessed at baseline and immediately after meal consumption. Appetite sensations were assessed in half-hour intervals from baseline to 1-h post-meal.

RESULTS

The area under the curve for subjective hunger (p < .001, ω = 0.36), desire to eat (p < .001, ω = 0.54), and prospective food consumption (p = .004, ω = 0.32) were significantly lower after consumption of the higher calorie meals relative to the lowest. Explicit wanting for sweet foods increased after intake of the intermediate calorie meal yet decreased after the highest calorie meal (p = .014, ω = 0.09). Conversely, implicit wanting sweet bias increased after consumption of the test meal independent of energy content (p < .001, ω = 0.15).

CONCLUSION

The consumption of additional calories without a meaningful change in macronutrient distribution may affect appetite sensations more reliably than hedonic responses to energy-dense foods in adolescents with obesity.

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.

Effect of acute dietary- versus combined dietary and exercise-induced energy deficits on subsequent energy intake, appetite and food reward in adolescents with obesity

BACKGROUND

Acute dietary-induced energy deficits have been shown to favor compensatory appetitive responses. The aim of this study was to compare energy intake (EI), appetite sensations and the hedonic responses to equivalent energy deficits induced by dietary restriction alone and combined with exercise in adolescents with obesity.

METHODS

In a within-subjects design, seventeen adolescents with obesity (12-16 years, Tanner stage 3-5, 6 males) randomly completed three 14 h conditions: (i) control (CON); (ii) deficit induced by diet only (Def-EI) and; (iii) deficit induced by combined diet and physical exercise (Def-mixed). Breakfast and lunch were calibrated to generate a 500 kcal deficit in Def-EI and 250 kcal deficit in Def-mixed. A 250 kcal deficit was created through a cycling exercise set at 65% VO_2peak in Def-mixed. Ad libitum EI, macronutrients and relative EI (REI) were assessed at dinner, subjective appetite sensations taken at regular intervals, and food reward measured before dinner.

RESULTS

EI at dinner was significantly lower in Def-EI compared to CON (p = 0.014; Effect size (ES): -0.59 [-1.07; -0.12]), with no difference between Def-mixed and both CON and Def-EI. Total REI was lower in both deficit conditions compared with CON (Def-mixed: p < 0.001; ES: -3.80 [-4.27; -3.32], Def-EI: p < 0.001; ES: -4.90 [-5.37; -4.42] respectively), indicating incomplete compensation for the energy deficits. Absolute protein ingestion at dinner was lower in Def-EI than Def-mixed (p = 0.037; ES: -0.50 [-0.98; -0.03]) and absolute lipid ingestion was lower in Def-EI than in CON (p = 0.033; ES: -0.51 [-0.99; -0.04]). A higher proportion of protein and a lower proportion of carbohydrates was observed in Def-mixed than in Def-EI (p = 0.078; ES: -0.42 [-0.90; 0.04] and p = 0.067; ES: 0.44 [-0.03; 0.92] respectively). Total area under the curve for appetite sensations were similar between conditions. Explicit liking for sweet relative to savoury food was lower in Def-mixed compared to CON (p = 0.027; ES: -0.53 [-1.01; -0.06]) with no difference in food reward between Def-EI and CON.

CONCLUSION

Neither of the two acute isoenergetic deficits led to subsequent appetitive compensation, with the dietary deficit even inducing a lower ad libitum EI at the subsequent dinner. Further studies are needed to better understand the appetitive response to dietary and exercise energy balance manipulations in this population.

Post-exercise energy intake: do the intensity and mode of exercise matter? A systematic review and meta-analysis comparing high-intensity interval with moderate-intensity continuous protocols

The present systematic review and meta-analysis aimed to compare the impact of exercise intensity and mode (high-intensity interval exercise-HIIE or sprint interval exercise-SIE versus moderate-intensity continuous exercise-MICE) on post-exercise ad libitum energy intake. The studies were required to have at least two exercise conditions (HIIE or SIE vs MICE). Overall, 642 manuscripts were initially identified and 17 met the eligibility criteria. The random effect meta-analysis did not reveal differences for absolute energy intake (28 pairwise comparisons) between HIIE (p = 0.54; 95% Confidence Interval - CI: -0.14 to 0.26; 22 pairwise comparisons) or SIE (p = 0.08; 95% CI -0.65 to 0.03; 6 pairwise comparisons) versus MICE, neither for relative energy intake (p = 0.97; 95% CI: -0.35 to 0.10 for HIIE; p = 0.28; 95% CI: -1.03 to 0.06 for SIE) with five and one pairwise comparisons, respectively. Subgroup analyses for methods to evaluate ad libitum energy intake, body mass, sex, volume, and timing of exercise were non-significant. Inspecting each study, two pairwise comparisons reported lower post-exercise absolute energy intake in HIIE compared to control (CRTL), and three pairwise comparisons reported lower absolute energy intake after SIE compared to MICE. None pairwise comparison reported differences between protocols (HIIE or SIE versus MICE) for relative energy intake. In conclusion, the meta-analysis did not show differences between protocols for absolute and relative energy intake; five pairwise comparisons from 28 demonstrated lower absolute energy intake in HIIE or SIE compared to CRTL or MICE. Further studies are needed to address the key relevant variables in which exercise intensity and mode may impact energy intake.

Characteristics and antifatigue activity of graded polysaccharides from Ganoderma lucidum separated by cascade membrane technology

In this paper, cascade membrane technology was utilized to classify polysaccharides from Ganoderma lucidum (GLPs). The properties and antifatigue activity of graded polysaccharides were identified and compared. GLPs were separated using cascade ultrafiltration membranes of 100 kDa, 10 kDa and 1 kDa in sequence. The molecular weights of polysaccharides in these GLP fractions were approximately 322.0 kDa, 18.8 kDa and 6.4 kDa, and all polysaccharides were in active β-configurations. This showed that all graded GLPs could elongate swimming time, improve endurance and promote fatigue recovery, especially polysaccharides with molecular weights above 10 kDa. This demonstrated that GLPs could decrease the activities of SUN and CK and the levels of MDA and BLA. They also increased the level of Gly, accelerated fat transformation, and improved the activities of GPx, SOD and LDH in all treated mice. Accordingly, GLPs above 10 kDa might be potential agents with antifatigue activity.

Adipose Tissue Development and Expansion from the Womb to Adolescence: An Overview

Prevalence rates of pediatric obesity continue to rise worldwide. Adipose tissue (AT) development and expansion initiate in the fetus and extend throughout the lifespan. This paper presents an overview of the AT developmental trajectories from the intrauterine period to adolescence; factors determining adiposity expansion are also discussed. The greatest fetal increases in AT were observed in the third pregnancy trimester, with growing evidence suggesting that maternal health and nutrition, toxin exposure, and genetic defects impact AT development. From birth up to six months, healthy term newborns experience steep increases in AT; but a subsequent reduction in AT is observed during infancy. Important determinants of AT in infancy identified in this review included feeding practices and factors shaping the gut microbiome. Low AT accrual rates are maintained up to puberty onset, at which time, the pattern of adiposity expansion becomes sex dependent. As girls experience rapid increases and boys experience decreases in AT, sexual dimorphism in hormone secretion can be considered the main contributor for changes. Eating patterns/behaviors and interactions between dietary components, gut microbiome, and immune cells also influence AT expansion. Despite the plasticity of this tissue, substantial evidence supports that adiposity at birth and infancy highly influences its levels across subsequent life stages. Thus, a unique window of opportunity for the prevention and/or slowing down of the predisposition toward obesity, exists from pregnancy through childhood.

Delayed meal timing after exercise is associated with reduced appetite and energy intake in adolescents with obesity

BACKGROUND

While the beneficial effects of exercise on appetite might depend on its timing during the day or relative to a meal, this remains poorly explored in youth.

OBJECTIVES

To examine the importance of meal timing (+30 vs +90 minutes) after performing exercise on energy intake, appetite and food reward in adolescents with obesity.

METHODS

Eighteen adolescents with obesity randomly completed three conditions: (a) lunch (12:00 pm) set 30 minutes after a rest session (11:00 am); (b) lunch (12:00 pm) set 30 minutes after an exercise session (11:00 am)(MEAL-30); (c) lunch (01:00 pm) set 90 minutes after an exercise session (11:00 am)(MEAL-90). Lunch and dinner ad libitum energy intake was assessed, food reward (LFPQ) assessed before and after lunch, and before dinner, appetite sensations were assessed at regular intervals.

RESULTS

Energy intake was lower at MEAL-90 than MEAL-30 and CON at lunch (P < .05 and P < .01, respectively) and lunch + dinner combined (P < .001). A decrease in intake (g) of protein, fat and carbohydrate was observed. Post-exercise hunger was lower on MEAL-90 compared with CON. No condition effects were found at lunch for food reward.

CONCLUSIONS

Delaying the timing of the meal after exercise might help affect energy balance by decreasing ad libitum energy intake without increasing hunger and by improving satiety in adolescents with obesity.

Obesity does not modulate men's eating behavior after a high intensity interval exercise session: an exercise trial

BACKGROUND

We investigated the impact of obesity on responses to high intensity interval exercise (HIIE) on hunger and energy intake (EI) in young men.

METHODS

Ten men with obesity (OB) (Body Mass Index [BMI]: 34.6±4.4 kg/m²) and 10 with normal weight (CG) (BMI: 23.1±3.9 kg/m²) participated in a HIIE session. The session consisted of 6 rounds performed at 100% of maximum aerobic velocity (MAV) for 30 seconds, followed by 30 seconds of active recovery at 50% MAV and concluded with 4 minutes of passive recovery. This was repeated three times. EI was estimated at baseline and 24 h-post-HIIE. Hunger was measured at baseline, 2 h- and 24 h-post HIIE.

RESULTS

Carbohydrate (CHO) intake increased in both groups (P<0.01). Hunger feelings (19.5 [0-50] mm at baseline to 50 [9-73] mm post-2 h and 60 [8-92] mm in post-24 h [group: P=0.71, time: P<0.01, group × time: P=0.06]) and a desire to eat (34 [1-89] ±36.0 mm at baseline to 63 [11-86] mm post-2 h and 51 [7-84] mm post-24 h [group: P=0.65, time: P<0.01, group × time: P=0.29]) increased in both groups.

CONCLUSIONS

Weight status does not modulate hunger and EI post-HIIE. However, the compensatory increase in CHO intake and hunger feelings is particularly noteworthy for health professionals.

A systematic review of the use of the Satiety Quotient

The satiating efficiency of food has been increasingly quantified using the Satiety Quotient (SQ). The SQ integrates both the energy content of food ingested during a meal and the associated change in appetite sensations. This systematic review examines the available evidence regarding its methodological use and clinical utility. A literature search was conducted in six databases considering studies from 1900 to April 2020 that used SQ in adults, adolescents and children. All study designs were included. From the initial 495 references found, fifty-two were included. Of the studies included, thirty-three were acute studies (twenty-nine in adults and four in adolescents) and nineteen were longitudinal studies in adults. A high methodological heterogeneity in the application of the SQ was observed between studies. Five main utilisations of the SQ were identified: its association with (i) energy intake; (ii) anthropometric variables; (iii) energy expenditure/physical activity; (iv) sleep quality and quantity and (v) to classify individuals by their satiety responsiveness (i.e. low and high satiety phenotypes). Altogether, the studies suggest the SQ as an interesting clinical tool regarding the satiety responsiveness to a meal and its changes in responses to weight loss in adults. The SQ might be a reliable clinical indicator in adults when it comes to both obesity prevention and treatment. There is a need for more standardised use of the SQ in addition to further studies to investigate its validity in different contexts and populations, especially among children and adolescents.

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.