title: A carbohydrate-restricted diet during resistance training promotes more favorable changes in body composition and markers of health in obese women with and without insulin resistance.
abstract: OBJECTIVE
  To determine whether sedentary obese women with elevated levels of homeostatic model assessment (HOMA) insulin resistance (ie, > 3.5) experience greater benefits from an exercise + higher-carbohydrate (HC) or carbohydrate-restricted weight loss program than women with lower HOMA levels.
  
  
  METHODS
  221 women (age, 46.5 ± 12 years; body weight, 90.3 ± 16 kg; body mass index, 33.8 ± 5 kg/m(2)) participated in a 10-week supervised exercise and weight loss program. The fitness program involved 30 minutes of circuit-style resistance training 3 days per week. Subjects were prescribed low-fat (30%) isoenergetic diets that consisted of 1200 kcals per day for 1 week (phase 1) and 1600 kcals per day for 9 weeks (phase 2) with HC or higher protein (HP). Fasting blood samples, body composition, anthropometry, resting energy expenditure, and fitness measurements were obtained at 0 and 10 weeks. Subjects were retrospectively stratified into lower (LH) or higher (HH) than 3.5 HOMA groups. Data were analyzed by multivariate analysis of variance with repeated measures and are presented as mean ± standard deviation changes from baseline.
  
  
  RESULTS
  Baseline HOMA levels in the LH group were significantly lower than those in the HH group (LH, 0.6 ± 0.7; HH, 6.3 ± 3.4; P = 0.001). Diet and training significantly decreased body weight (-3.5 ± 3 kg), fat mass (-2.7 ± 3 kg), blood glucose (-3%), total cholesterol (-4.5%), low-density lipoproteins (-5%), triglycerides (-5.9%), systolic blood pressure (-2.6%), and waist circumference (-3.7%), while increasing peak aerobic capacity (7.3%). Subjects in the HP group experienced greater weight loss (-4.4 ± 3.6 kg vs -2.6 ± 2.9 kg), fat loss (-3.4 ± 2.7 kg vs -1.7 ± 2.0 kg), reductions in serum glucose (3% vs 2%), and decreases in serum leptin levels (-30.8% vs -10.8%) than those in the HC group. Participants in the HH (-14.1%) and HP-HH (-21.6%) groups observed the greatest reduction in serum blood glucose.
  
  
  CONCLUSIONS
  A carbohydrate-restricted diet promoted more favorable changes in weight loss, fat loss, and markers of health in obese women who initiated an exercise program compared with a diet higher in carbohydrate. Additionally, obese women who initiated training and dieting with higher HOMA levels experienced greater reductions in blood glucose following an HP diet.
authors.affiliation: Department of Health and Kinesiology, Texas A&M University, College Station, TX, USA. rkreider@hlkn.tamu.edu
authors.forename: Richard B
authors.initials: RB
authors.lastname: Kreider
authors.forename: Christopher
authors.initials: C
authors.lastname: Rasmussen
authors.forename: Chad M
authors.initials: CM
authors.lastname: Kerksick
authors.forename: Colin
authors.initials: C
authors.lastname: Wilborn
authors.forename: Lemuel
authors.initials: L
authors.lastname: Taylor
authors.forename: Bill
authors.initials: B
authors.lastname: Campbell
authors.forename: Teresa
authors.initials: T
authors.lastname: Magrans-Courtney
authors.forename: Donovan
authors.initials: D
authors.lastname: Fogt
authors.forename: Maria
authors.initials: M
authors.lastname: Ferreira
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.forename: Melyn
authors.initials: M
authors.lastname: Galbreath
authors.forename: Mike
authors.initials: M
authors.lastname: Iosia
authors.forename: Matt
authors.initials: M
authors.lastname: Cooke
authors.forename: Monica
authors.initials: M
authors.lastname: Serra
authors.forename: Jean
authors.initials: J
authors.lastname: Gutierrez
authors.forename: Mike
authors.initials: M
authors.lastname: Byrd
authors.forename: Julie Y
authors.initials: JY
authors.lastname: Kresta
authors.forename: Sunday
authors.initials: S
authors.lastname: Simbo
authors.forename: Jonathan
authors.initials: J
authors.lastname: Oliver
authors.forename: Mike
authors.initials: M
authors.lastname: Greenwood
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood*; D001786:Blood Glucose / Q000378:metabolism; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D050528:Diet, Carbohydrate-Restricted; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000178:diet therapy / Q000534:rehabilitation*; D055070:Resistance Training / Q000379:methods*; D015431:Weight Loss / Q000502:physiology*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001786:Blood Glucose