title: The relationship between pretreatment dietary composition and weight loss during a randomised trial of different diet approaches.
abstract: BACKGROUND
  Identifying pretreatment dietary habits that are associated with weight-loss intervention outcomes could help guide individuals' selection of weight-loss approach among competing options. A pretreatment factor that may influence weight-loss outcomes is macronutrient intake.
  
  
  METHODS
  Overweight and obese Durham Veterans Affairs outpatients were randomised to a weight-loss intervention with a low-carbohydrate diet (n = 71) or orlistat medication therapy plus a low-fat diet (n = 73). Percentage fat, carbohydrate and protein intake prior to treatment were measured using 4-day food records. Linear mixed-effects models were used to determine whether pretreatment percentage macronutrient intake influenced weight trajectories and weight loss in each weight-loss condition.
  
  
  RESULTS
  Participant's mean age was 53 years, baseline body mass index was 39.3 kg m(-2) and 72% were male. A higher pretreatment percentage carbohydrate intake was associated with less rapid initial weight loss (P = 0.02) and less rapid weight regain (P = 0.03) in the low-carbohydrate diet condition but was not associated with weight trajectories in the orlistat plus low-fat diet condition. In both conditions, a higher pretreatment percentage fat intake was associated with more rapid weight regain (P < 0.01). Pretreatment percentage protein intake was not associated with weight trajectories. None of the pretreatment macronutrients were associated with weight loss on study completion in either condition.
  
  
  CONCLUSIONS
  Selection of a weight-loss approach on the basis of pretreatment macronutrient intake is unlikely to improve weight outcomes at the end of a 1-year treatment. However, pretreatment macronutrient intake may have implications for tailoring of interventions to slow weight regain after weight loss.
authors.affiliation: Center for Health Services Research in Primary Care, Durham VA Medical Center, Durham, NC, USA; Division of General Internal Medicine, Department of Medicine, Duke University, Durham, NC, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: McVay
authors.forename: A S
authors.initials: AS
authors.lastname: Jeffreys
authors.forename: H A
authors.initials: HA
authors.lastname: King
authors.forename: M K
authors.initials: MK
authors.lastname: Olsen
authors.forename: C I
authors.initials: CI
authors.lastname: Voils
authors.forename: W S
authors.initials: WS
authors.lastname: Yancy
mesh_terms: D000328:Adult; D019440:Anti-Obesity Agents / Q000627:therapeutic use; D050528:Diet, Carbohydrate-Restricted; D018752:Diet, Fat-Restricted; D004038:Diet, Reducing; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage*; D002149:Energy Intake; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D007783:Lactones / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy* / Q000188:drug therapy; D000077403:Orlistat; D015430:Weight Gain; D015431:Weight Loss
chemical_list: D019440:Anti-Obesity Agents; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D007783:Lactones; D000077403:Orlistat
keywords: carbohydrate-restricted diet; dietary carbohydrates; dietary fats; orlistat; weight loss