• Energy Research
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Exercise has been shown to decrease subsequent energy intake, without modification of appetite, in adolescents who are obese. This study compared the impact of acute exercise with imposed sedentary behaviors on the daily nutritional adaptations and energy balance of youths with obesity.Body composition and maximal oxygen uptake were assessed in 10 12- to 15-year-old adolescents with obesity. Energy consumption, appetite, and energy expenditure were assessed during 3 experimental sessions: (1) exercise session (EX), (2) bed rest session (BR), and (3) control session (CON).Total and morning energy expenditures were significantly higher during EX compared to CON and BR sessions (p < .001), and no differences were found during the afternoon energy expenditure between conditions (BR: 1056.5 ± 121.5; CON: 1185.7 ± 173; EX: 996.1 ± 153.4 Kcal). Total energy intake was significantly reduced on EX (p < .001). Dinner energy intake was significantly reduced during EX (491.65 ± 75.74 Kcal) and CON (666.55 ± 152.09 Kcal) compared with BR (818.87 ± 122.97 Kcal) (p < .001). Appetite was not affected.Whereas intense exercise reduces daily energy balance in adolescents with obesity by mainly affecting ad libitum dinner energy consumption, imposed sedentary behaviors lead to increased energy intake and then positive energy balance. The impact of exercise or imposed sedentary behaviors on the energy balance of adolescents with obesity is not only related to the exercise-induced energy expenditure, but also to their energy intake.

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.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.Daily, morning and afternoon energy expenditure were significantly higher in obese than in normal weight adolescents (p0.05) but not in lean adolescents. No group or condition effects were observed on subjective appetite feelings.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.

Diet-induced weight loss is often limited in its magnitude and often of short duration, followed by weight regain. On the contrary, bariatric surgery now commonly used in the treatment of severe obesity favors large and sustained weight loss, with resolution or improvement of most obesity-associated comorbidities. The mechanisms of sustained weight loss are not well understood. Whether changes in the various components of energy expenditure favor weight maintenance after bariatric surgery is unclear. While the impact of diet-induced weight loss on energy expenditure has been widely studied and reviewed, the impact of bariatric surgery on total energy expenditure, resting energy expenditure, and diet-induced thermogenesis remains unclear. Here, we review data on energy expenditure after bariatric surgery from animal and human studies. Bariatric surgery results in decreased total energy expenditure, mainly due to reduced resting energy expenditure and explained by a decreased in both fat-free mass and fat mass. Limited data suggest increased diet-induced thermogenesis after gastric bypass, a surgery that results in gut anatomical changes and modified the digestion processes. Physical activity and sustained intakes of dietary protein may be the best strategies available to increase non-resting and then total energy expenditure, as well as to prevent the decline in lean mass and resting energy expenditure.

Acute exercise can affect the energy intake regulation, which is of major interest in terms of obesity intervention and weight loss.To test the hypothesis that intensive exercise can affect the subsequent energy intake and balance in obese adolescents.The study was conducted in 2009 and enrolled 12 obese pubertal adolescents ages 14.4±1.5 years old. Two exercise and one sedentary sessions were completed. The first exercise (EX(1)) and sedentary session (SED) were randomly conducted 1 week apart. The second exercise session (EX₂) was conducted following 6 weeks of diet modification and physical activity (3×90 min/week) to produce weight loss. Energy intake was recorded, subjective appetite sensation was evaluated using Visual Analogue Scales and energy expenditure was measured using ActiHerats during EX(1), EX₂ and SED.Total energy intake over the awakened period was significantly reduced by 31% and 18% during the EX(1) and EX(2) sessions compared with the SED session, respectively (p<0.01). Energy balance over the awakened period was negative during EX₁, neutral during EX₂ and positive during SED. There was no significant difference in terms of subjective appetite rates between sessions during the awakened hours.Intensive exercise favors a negative energy balance by dually affecting energy expenditure and energy intake without changes in appetite sensations, suggesting that adolescents are not at risk of food frustration.