title: Independent, additive effects of five dietary variables on ad libitum energy intake in a residential study.
abstract: OBJECTIVE
  To examine the relationship between dietary characteristics of self-selected foods and energy balance in a cafeteria-style dining hall.
  
  
  METHODS
  Ad libitum dietary intake from a self-selection menu was measured over two days in 151 adults (70% female, mean age 41 years, mean BMI 24.9 kg/m(2) ). The associations of dietary variables with energy balance (calculated as measured energy intake/predicted energy requirements, pER) were assessed.
  
  
  RESULTS
  Measured energy intake was significantly correlated with pER (R(2) =0.83, P < 0.001). In mixed multiple regression models, percent energy from protein was negatively associated with energy balance (R(2) =0.04, P = 0.02), and percent energy from liquid sources (R(2)  = 0.02, P = 0.05), total dietary variety in females (R(2)  = 0.39, P < 0.001), and energy density (R(2)  = 0.57, P < 0.001) were positively associated with energy balance. In addition, glycemic index was inversely associated with energy balance in normal-weight individuals (R(2)  = 0.14, P < 0.001) but not in overweight or obese individuals.
  
  
  CONCLUSIONS
  There are independent associations of dietary protein, liquid calories, energy density, dietary variety, and glycemic index with energy balance, indicating additive effects of these dietary factors on energy intake and energy balance. Intervention studies are needed to determine whether dietary prescriptions combining these dietary factors facilitate long-term prevention of weight gain.
authors.affiliation: Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts, USA.
authors.forename: Lorien E
authors.initials: LE
authors.lastname: Urban
authors.forename: Megan A
authors.initials: MA
authors.lastname: McCrory
authors.forename: Helen
authors.initials: H
authors.lastname: Rasmussen
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Greenberg
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Fuss
authors.forename: Edward
authors.initials: E
authors.lastname: Saltzman
authors.forename: Susan B
authors.initials: SB
authors.lastname: Roberts
mesh_terms: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage; D004044:Dietary Proteins; D002149:Energy Intake / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D005518:Food Preferences / Q000502:physiology; D038321:Glycemic Index; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism; D050177:Overweight / Q000378:metabolism; D014427:Twins; D055815:Young Adult
chemical_list: D004041:Dietary Fats; D004044:Dietary Proteins