title: Self-Directed Weight Loss Strategies: Energy Expenditure Due to Physical Activity Is Not Increased to Achieve Intended Weight Loss.
abstract: Reduced physical activity and almost unlimited availability of food are major contributors to the development of obesity. With the decline of strenuous work, energy expenditure due to spontaneous physical activity has attracted increasing attention. Our aim was to assess changes in energy expenditure, physical activity patterns and nutritional habits in obese subjects aiming at self-directed weight loss.
  
  
  METHODS
  Energy expenditure and physical activity patterns were measured with a portable armband device. Nutritional habits were assessed with a food frequency questionnaire.
  
  
  RESULTS
  Data on weight development, energy expenditure, physical activity patterns and nutritional habits were obtained for 105 patients over a six-month period from an initial cohort of 160 outpatients aiming at weight loss. Mean weight loss was -1.5 ± 7.0 kg (p = 0.028). Patients with weight maintenance (n = 75), with substantial weight loss (>5% body weight, n = 20) and with substantial weight gain (>5% body weight, n = 10) did not differ in regard to changes of body weight adjusted energy expenditure components (total energy expenditure: -0.2 kcal/kg/day; non-exercise activity thermogenesis: -0.3 kcal/kg/day; exercise-related activity thermogenesis (EAT): -0.2 kcal/kg/day) or patterns of physical activity (duration of EAT: -2 min/day; steps/day: -156; metabolic equivalent unchanged) measured objectively with a portable armband device. Self-reported consumption frequency of unfavorable food decreased significantly (p = 0.019) over the six-month period.
  
  
  CONCLUSIONS
  An increase in energy expenditure or changes of physical activity patterns (objectively assessed with a portable armband device) are not employed by obese subjects to achieve self-directed weight loss. However, modified nutritional habits could be detected with the use of a food frequency questionnaire.
authors.affiliation: Department of Endocrinology, Diabetes and Nutrition, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany. ulf.elbelt@charite.de.
authors.forename: Ulf
authors.initials: U
authors.lastname: Elbelt
authors.affiliation: Integrated Research and Treatment Center (IFB) Adiposity Diseases, Core Unit Nutrition and Clinical Phenotyping, Leipzig University Medical Center, Philipp-Rosenthal-Straße 27, 04103 Leipzig, Germany. tatjana.schuetz@medizin.uni-leipzig.de.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Schuetz
authors.affiliation: Health Psychology Department, Freie Universität Berlin, Habelschwerdter Allee 45, 14195 Berlin, Germany. nina.knoll@fu-berlin.de.
authors.forename: Nina
authors.initials: N
authors.lastname: Knoll
authors.affiliation: Institute of Medical Psychology, Charité-Universitätsmedizin Berlin, Luisenstraße 57, 10117 Berlin, Germany. silke.burkert@charite.de.
authors.forename: Silke
authors.initials: S
authors.lastname: Burkert
mesh_terms: D000328:Adult; D015331:Cohort Studies; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009043:Motor Activity; D050177:Overweight / Q000628:therapy*; D015431:Weight Loss
keywords: energy expenditure; nutritional habits; physical activity pattern; self-directed weight loss