title: Low-fat dietary pattern and change in body-composition traits in the Women's Health Initiative Dietary Modification Trial.
abstract: BACKGROUND
  The Women's Health Initiative Dietary Modification (DM) Trial was a randomized controlled trial that compared the effects of a low-fat (≤20% of total energy) or a usual diet in relation to chronic disease risk in postmenopausal women.
  
  
  OBJECTIVE
  We characterized long-term body-composition changes associated with the DM trial and potential modifiers of these associations.
  
  
  METHODS
  In the DM trial, 48,835 women aged 50-79 y were randomly assigned to intervention (40%) or comparison (60%) groups. We studied a subset with whole-body dual-energy X-ray absorptiometry scans at baseline and during follow-up. Changes in fat mass (FM), lean mass (LM), and percentage body fat between the intervention (n = 1580) and comparison (n = 2731) groups at years 1, 3, and 6 were compared. By using generalized estimating equations, we calculated overall differences between groups and tested for interactions with age, diabetes, race-ethnicity (white, black, and Hispanic), body mass index (BMI), and hormone therapy (HT).
  
  
  RESULTS
  The intervention women experienced significantly greater reductions in percentage body fat, FM, and LM at years 1 and 3 than did women in the comparison group (all P < 0.05). At year 6, only the FM change was significantly different between groups. Overall, the intervention was associated with reductions in percentage body fat (-0.8%; 95% CI: -1.0%, -0.6%), FM (-1.1 kg; 95% CI: -1.3, -0.8 kg), and LM (-0.17 kg; 95% CI: -0.28, -0.06 kg) during follow-up (all P < 0.003). Intervention associations varied by race-ethnicity, BMI, diabetes, and HT and remained significant after adjustment for physical activity.
  
  
  CONCLUSIONS
  This intervention was associated with modest long-term body-composition changes; the findings were more robust in years 1 and 3. This trial was registered at clinicaltrials.gov as NCT00000611.
authors.affiliation: Fred Hutchinson Cancer Research Center, Seattle, WA, USA. ccarty@whi.org
authors.forename: Cara L
authors.initials: CL
authors.lastname: Carty
authors.forename: Charles
authors.initials: C
authors.lastname: Kooperberg
authors.forename: Marian L
authors.initials: ML
authors.lastname: Neuhouser
authors.forename: Lesley
authors.initials: L
authors.lastname: Tinker
authors.forename: Barbara
authors.initials: B
authors.lastname: Howard
authors.forename: Jean
authors.initials: J
authors.lastname: Wactawski-Wende
authors.forename: Shirley A A
authors.initials: SA
authors.lastname: Beresford
authors.forename: Linda
authors.initials: L
authors.lastname: Snetselaar
authors.forename: Mara
authors.initials: M
authors.lastname: Vitolins
authors.forename: Matthew
authors.initials: M
authors.lastname: Allison
authors.forename: Nicole
authors.initials: N
authors.lastname: Budrys
authors.forename: Ross
authors.initials: R
authors.lastname: Prentice
authors.forename: Ulrike
authors.initials: U
authors.lastname: Peters
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D000375:Aging; D001823:Body Composition; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000453:epidemiology / Q000208:ethnology / Q000517:prevention & control; D002908:Chronic Disease / Q000453:epidemiology* / Q000208:ethnology / Q000517:prevention & control; D003110:Colonic Neoplasms / Q000453:epidemiology / Q000208:ethnology / Q000517:prevention & control; D003327:Coronary Disease / Q000453:epidemiology / Q000208:ethnology / Q000517:prevention & control; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000188:drug therapy; D018752:Diet, Fat-Restricted; D005260:Female; D006801:Humans; D008875:Middle Aged; D050177:Overweight / Q000150:complications / Q000178:diet therapy*; D010349:Patient Compliance; D017698:Postmenopause; D012307:Risk Factors