title: Weight and metabolic outcomes after 2 years on a low-carbohydrate versus low-fat diet: a randomized trial.
abstract: BACKGROUND
  Previous studies comparing low-carbohydrate and low-fat diets have not included a comprehensive behavioral treatment, resulting in suboptimal weight loss.
  
  
  OBJECTIVE
  To evaluate the effects of 2-year treatment with a low-carbohydrate or low-fat diet, each of which was combined with a comprehensive lifestyle modification program.
  
  
  METHODS
  Randomized parallel-group trial. (ClinicalTrials.gov registration number: NCT00143936)
  
  
  METHODS
  3 academic medical centers.
  
  
  METHODS
  307 participants with a mean age of 45.5 years (SD, 9.7 years) and mean body mass index of 36.1 kg/m(2) (SD, 3.5 kg/m(2)).
  
  
  METHODS
  A low-carbohydrate diet, which consisted of limited carbohydrate intake (20 g/d for 3 months) in the form of low-glycemic index vegetables with unrestricted consumption of fat and protein. After 3 months, participants in the low-carbohydrate diet group increased their carbohydrate intake (5 g/d per wk) until a stable and desired weight was achieved. A low-fat diet consisted of limited energy intake (1200 to 1800 kcal/d; <or=30% calories from fat). Both diets were combined with comprehensive behavioral treatment.
  
  
  METHODS
  Weight at 2 years was the primary outcome. Secondary measures included weight at 3, 6, and 12 months and serum lipid concentrations, blood pressure, urinary ketones, symptoms, bone mineral density, and body composition throughout the study.
  
  
  RESULTS
  Weight loss was approximately 11 kg (11%) at 1 year and 7 kg (7%) at 2 years. There were no differences in weight, body composition, or bone mineral density between the groups at any time point. During the first 6 months, the low-carbohydrate diet group had greater reductions in diastolic blood pressure, triglyceride levels, and very-low-density lipoprotein cholesterol levels, lesser reductions in low-density lipoprotein cholesterol levels, and more adverse symptoms than did the low-fat diet group. The low-carbohydrate diet group had greater increases in high-density lipoprotein cholesterol levels at all time points, approximating a 23% increase at 2 years.
  
  
  CONCLUSIONS
  Intensive behavioral treatment was provided, patients with dyslipidemia and diabetes were excluded, and attrition at 2 years was high.
  
  
  CONCLUSIONS
  Successful weight loss can be achieved with either a low-fat or low-carbohydrate diet when coupled with behavioral treatment. A low-carbohydrate diet is associated with favorable changes in cardiovascular disease risk factors at 2 years.
  
  
  BACKGROUND
  National Institutes of Health.
authors.affiliation: Center for Obesity Research and Education, Temple University, Philadelphia, Pennsylvania 19140, USA. gfoster@temple.edu
authors.forename: Gary D
authors.initials: GD
authors.lastname: Foster
authors.forename: Holly R
authors.initials: HR
authors.lastname: Wyatt
authors.forename: James O
authors.initials: JO
authors.lastname: Hill
authors.forename: Angela P
authors.initials: AP
authors.lastname: Makris
authors.forename: Diane L
authors.initials: DL
authors.lastname: Rosenbaum
authors.forename: Carrie
authors.initials: C
authors.lastname: Brill
authors.forename: Richard I
authors.initials: RI
authors.lastname: Stein
authors.forename: B Selma
authors.initials: BS
authors.lastname: Mohammed
authors.forename: Bernard
authors.initials: B
authors.lastname: Miller
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Rader
authors.forename: Babette
authors.initials: B
authors.lastname: Zemel
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Wadden
authors.forename: Thomas
authors.initials: T
authors.lastname: Tenhave
authors.forename: Craig W
authors.initials: CW
authors.lastname: Newcomb
authors.forename: Samuel
authors.initials: S
authors.lastname: Klein
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001521:Behavior Therapy; D001794:Blood Pressure; D001823:Body Composition; D015519:Bone Density; D050528:Diet, Carbohydrate-Restricted; D018752:Diet, Fat-Restricted; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D007657:Ketone Bodies / Q000652:urine; D008074:Lipoproteins / Q000097:blood; D008297:Male; D008875:Middle Aged; D050177:Overweight / Q000178:diet therapy / Q000378:metabolism / Q000628:therapy*; D016896:Treatment Outcome; D015431:Weight Loss; D055815:Young Adult
chemical_list: D007657:Ketone Bodies; D008074:Lipoproteins