Effects of carbohydrate quantity and glycemic index on resting metabolic rate and body composition during weight loss

• Published in: Obesity (Silver Spring, Md.) Md.), 2015-11, Vol.23 (11), p.2190-2198
• Main Authors: Karl, J. Philip, Roberts, Susan B., Schaefer, Ernst J., Gleason, Joi A., Fuss, Paul, Rasmussen, Helen, Saltzman, Edward, Das, Sai Krupa
• Format: Article
• Language: English
• Subjects: Aged; Basal Metabolism - drug effects; Body Composition - drug effects; Body Weight - drug effects; Carbohydrates; Diet; Dietary Carbohydrates - pharmacology; Female; Glycemic Index - physiology; Glycemic Load - physiology; Humans; Male; Middle Aged; Nutrition research; Obesity; Obesity - diet therapy; Obesity - metabolism; Studies; Weight Loss - drug effects
• ISSN: 1930-7381; 1930-739X
• DOI: 10.1002/oby.21268

Objective To examine the effects of diets varying in carbohydrate and glycemic index (GI) on changes in body composition, resting metabolic rate (RMR), and metabolic adaptation during and after weight loss. Methods Adults with obesity (n = 91) were randomized to one of four provided‐food diets for 17 weeks. Diets differed in percentage energy from carbohydrate (55% or 70%) and GI (low or high) but were matched for protein, fiber, and energy. Body weight, body composition, RMR, and metabolic adaptation (measured RMR–predicted RMR) were measured during weight loss and subsequent weight stability. Results No effect of dietary carbohydrate content or GI on body weight loss or percentage of weight lost as fat mass (FM) was observed. Measured RMR was significantly lower (−226 kJ/day [95% CI: −314 to −138 kJ/day], P