title: Effects of two weight-loss diets on health-related quality of life.
abstract: OBJECTIVE
  To compare the effects of two diets on health-related quality of life (HRQOL).
  
  
  METHODS
  Overweight volunteers (n = 119) were randomized to follow a low-carbohydrate, ketogenic diet (LCKD) or a low-fat diet (LFD) for 24 weeks. HRQOL was measured every 4 weeks using the Short Form-36 and analyzed using linear mixed-effects models.
  
  
  RESULTS
  The mean age was 45 years and mean baseline body mass index was 34 kg/m(2); 76% were women. At 24 weeks, five subscales (Physical Functioning, Role-Physical, General Health, Vitality, Social Functioning) and the Physical Component Summary score improved similarly in both diet groups. Bodily Pain improved in the LFD group only, whereas the Role-Emotional and Mental Health subscales and the Mental Component Summary (MCS) score improved in the LCKD group only. In comparison with the LFD group, the LCKD group had a statistically significant greater improvement in MCS score (3.1; 95%CI 0.2-6.0; effect size = 0.44) and a borderline significant greater improvement in the Mental Health subscale (5.0; 95%CI -0.3-10.4; effect size = 0.37).
  
  
  CONCLUSIONS
  Mental aspects of HRQOL improved more in participants following an LCKD than an LFD, possibly resulting from the LCKD's composition, lack of explicit energy restriction, higher levels of satiety or metabolic effects.
authors.affiliation: Center for Health Services Research in Primary Care, Department of Veterans Affairs Medical Center, 508 Fulton Street, Durham, NC, 27705, USA. yancy006@mc.duke.edu
authors.forename: William S
authors.initials: WS
authors.lastname: Yancy
authors.forename: Daniel
authors.initials: D
authors.lastname: Almirall
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Maciejewski
authors.forename: Ronette L
authors.initials: RL
authors.lastname: Kolotkin
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: McDuffie
authors.forename: Eric C
authors.initials: EC
authors.lastname: Westman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004038:Diet, Reducing / Q000379:methods*; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D055815:Young Adult