title: Effects of a hypocaloric, low-carbohydrate diet on weight loss, blood lipids, blood pressure, glucose tolerance, and body composition in free-living overweight women.
abstract: The purpose of the current study was to examine the effects of a very low-carbohydrate diet on weight loss and biochemical parameters in overweight women. Twenty women completed an 8-week trial that reduced their daily carbohydrate intake from 232 to 71 g (p < 0.05) and reduced energy by 2,644 kJ/day (8,384 to 5,740 kJ, p < 0.001). The average weight loss was 5.0 kg (p < 0.0001), with a net decrease in body mass index of 1.82 kg/m2, a loss of 3.4% body fat (4 kg, p < 0.0001), and a loss of 1.0 kg lean mass (p < 0.05). There were no significant changes in fasting blood glucose, fasting serum insulin, oral glucose tolerance, free or total insulin-like growth factor-1, or total IGFBP-3. Systolicblood pressure decreased by an average of 9.0 mmHg (1 mmHg = 133.322 Pa) (p < 0.01) and diastolic blood pressure decreased by 7 mmHg (p < 0.05). Total cholesterol decreased 1.2 mM (p < 0.001), all of which was accounted for by a decrease in low-density lipoprotein cholesterol (p < 0.001) with no change in high-density lipoprotein cholesterol (baseline, 1.17 mM; week 8, 1.22 mM). Total triacylglycerol decreased 0.6 mM (p < 0.01), and the ratio of triacylglycerol/HDL also significantly decreased (baseline, 1.40; week 8, 0.87; p < 0.001). Serum beta-hydroxybutyrate concentrations rose significantly by week 2 and declined thereafter but remained significantly higher than baseline values for the duration of the intervention. Therefore, carbohydrate restriction to 70 g or less with concomitant energy restriction, without changes in protein or fat consumption, promotes weight loss, and improvements in body composition, blood pressure, and blood lipids without compromising glucose tolerance in moderately overweight women.
authors.affiliation: Department of Human Biology and Nutritional Sciences, University of Guelph, Guelph, ON NIG 2W1, Canada. kmecklin@uoguelph.ca
authors.forename: Kelly A
authors.initials: KA
authors.lastname: Meckling
authors.forename: Melanie
authors.initials: M
authors.lastname: Gauthier
authors.forename: Rebecca
authors.initials: R
authors.lastname: Grubb
authors.forename: Jennifer
authors.initials: J
authors.lastname: Sanford
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001794:Blood Pressure / Q000502:physiology*; D001823:Body Composition / Q000502:physiology; D031204:Caloric Restriction / Q000379:methods* / Q000706:statistics & numerical data; D004038:Diet, Reducing / Q000379:methods / Q000706:statistics & numerical data; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D005260:Female; D005951:Glucose Tolerance Test / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D008055:Lipids / Q000097:blood*; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000178:diet therapy*; D015431:Weight Loss / Q000502:physiology*
chemical_list: D004040:Dietary Carbohydrates; D008055:Lipids