title: The association of change in physical activity and body weight in the regulation of total energy expenditure.
abstract: The limited success in addressing the current obesity epidemic reflects the insufficient understanding of the regulation of energy balance. The present study examines the longitudinal association of body weight with physical activity (PA), total daily energy expenditure (TDEE) and total daily energy intake (TDEI).
  
  
  
  A total of 195 adults (52% male) between 21 and 35 years of age with no intention for weight loss were followed over a 2-year period. Body weight, fat mass and fat-free mass were measured every 3 months. Participants were stratified into three groups based on change in body weight using a 5% cutpoint. TDEE and time spent in different PA intensities were determined via a multisensor device at each measurement time. TDEI was calculated based on change in body composition and TDEE.
  
  
  
  At 2-year follow-up, 57% of the participants maintained weight, 14% lost weight and 29% gained weight. Average weight change was -6.9±3.4 and 7.1±3.6 kg in the weight-loss and weight-gain groups, respectively. Average TDEE and TDEI did not change significantly in any weight change group (P>0.16). Moderate-to-vigorous PA, however, increased significantly in the weight-loss group (35±49 min/day; P<0.01) and decreased in the weight-gain group (-35±46 min/day; P<0.01).
  
  
  
  Results of this observational study indicate an inverse association between body weight and PA to maintain a stable TDEE and allow for a stable TDEI over time. Sufficient PA levels, therefore, are an important contributor to weight loss maintenance.
authors.affiliation: Department of Exercise Science, University of South Carolina, Columbia, SC, USA.
authors.forename: C
authors.identifier: 0000-0002-3861-5364
authors.initials: C
authors.lastname: Drenowatz
authors.affiliation: School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
authors.forename: J O
authors.initials: JO
authors.lastname: Hill
authors.affiliation: School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Peters
authors.affiliation: Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain.|Department of Education, Faculty of Education Sciences, University of Almería, Almería, Spain.
authors.forename: A
authors.identifier: 0000-0002-4626-420X
authors.initials: A
authors.lastname: Soriano-Maldonado
authors.affiliation: Department of Exercise Science, University of South Carolina, Columbia, SC, USA.|Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, SC, USA.
authors.forename: S N
authors.initials: SN
authors.lastname: Blair
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D001823:Body Composition; D015992:Body Mass Index; D001835:Body Weight; D004032:Diet; D004734:Energy Metabolism; D015444:Exercise; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009765:Obesity / Q000378:metabolism; D050177:Overweight / Q000378:metabolism; D011446:Prospective Studies; D057185:Sedentary Behavior; D055815:Young Adult