title: Impact of imposed exercise on energy intake in children at risk for overweight.
abstract: Exercise not only has a direct effect on energy balance through energy expenditure (EE), but also has an indirect effect through its impact on energy intake (EI). This study examined the effects of acute exercise on daily ad libitum EI in children at risk for becoming overweight due to family history.
  
  
  
  Twenty healthy-weight children (ages 9-12 years, 12 male/8 female) with at least one overweight biological parent (body mass index ≥ 25 kg/m2) participated. Children reported to the laboratory for one baseline and two experimental visits (EX = exercise, SED = sedentary) each separated by 1 week in a randomized crossover design. Two hours into the EX day session, children exercised at 70 % estimated VO2maxfor 30 min on a cycle ergometer. Objective EI (kcal) was measured at a standard breakfast (~285 kcal) and ad libitum lunch, snack and dinner. Meals were identical on the EX and SED days. Activity-related EE (kcal) was estimated with accelerometers worn on the non-dominant wrist and ankle. Relative EI (kcal) was computed as the difference between Total EI and Activity-related EE for each testing day. Paired t-tests were performed to test differences in Total EI, Activity-related EE and Relative EI between the EX and SED days.
  
  
  
  Across all meals, Total EI was not statistically different between the EX and SED days (t = 1.8, p = 0.09). Activity-related EE was greater on the EX day compared to the SED day (t = 10.1, p < 0.001). By design, this difference was predominantly driven by activity during the morning (t = 20.4, p < 0.001). Because children consumed a similar number of kcal on each day, but had greater Activity-related EE on the EX day, Relative EI was lower (t = -5.15, p < 0.001) for the EX day (1636 ± 456 kcal) relative to the SED day (1862 ± 426 kcal).
  
  
  
  Imposed exercise was effective in reducing Relative EI compared to being sedentary. Morning exercise may help children at risk for becoming overweight to better regulate their energy balance within the course of a day.
authors: Department of Nutritional Sciences, The Pennsylvania State University, 110 Chandlee Laboratory, University Park, PA, 16802, USA. snf129@psu.edu.
authors: S Nicole
authors: SN
authors: Fearnbach
authors: Department of Nutritional Sciences, The Pennsylvania State University, 110 Chandlee Laboratory, University Park, PA, 16802, USA.
authors: Travis D
authors: TD
authors: Masterson
authors: Department of Nutritional Sciences, The Pennsylvania State University, 110 Chandlee Laboratory, University Park, PA, 16802, USA.
authors: Haley A
authors: HA
authors: Schlechter
authors: Department of Kinesiology, The Pennsylvania State University, 276 Recreation Building, University Park, PA, 16802, USA.
authors: Amanda J
authors: AJ
authors: Ross
authors: Department of Kinesiology, The Pennsylvania State University, 276 Recreation Building, University Park, PA, 16802, USA.
authors: Michael J
authors: MJ
authors: Rykaczewski
authors: Department of Human Development and Family Studies, The Pennsylvania State University, 119 Health and Human Development Building, University Park, PA, 16802, USA.|Department of Educational Psychology, University of Connecticut, 328 Charles B. Gentry Building, Storrs, CT, 06269, USA.
authors: Eric
authors: E
authors: Loken
authors: Department of Kinesiology, The Pennsylvania State University, 276 Recreation Building, University Park, PA, 16802, USA.
authors: Danielle S
authors: DS
authors: Downs
authors: Laboratory of the Metabolic Adaptations to Exercise under Physiological and Pathological Conditions (AME2P), Clermont Auvergne University, EA 3533, Clermont-Ferrand, France.|CRNH-Auvergne, 58 Rue Montalembert, 63009, Clermont-Ferrand, France.
authors: David
authors: D
authors: Thivel
authors: Department of Nutritional Sciences, The Pennsylvania State University, 110 Chandlee Laboratory, University Park, PA, 16802, USA.|Department of Food Science, The Pennsylvania State University, 202 Rodney A. Erickson Food Science Building, University Park, PA, 16802, USA.
authors: Kathleen L
authors: KL
authors: Keller
mesh_terms: D002648:Child; D018592:Cross-Over Studies; D004032:Diet; D002149:Energy Intake / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D062407:Meals; D050177:Overweight / Q000503:physiopathology*; D010101:Oxygen Consumption; D012307:Risk Factors; D013997:Time Factors
keywords: Children; Energy balance; Energy expenditure; Energy intake; Exercise; Obesity