Does metabolic compensation explain the majority of less-than-expected weight loss in obese adults during a short-term severe diet and exercise intervention?

• Published in: International Journal of Obesity 2012-11, Vol.36 (11), p.1472-1478
• Main Authors: Byrne, N M, Wood, R E, Schutz, Y, Hills, A P
• Format: Article
• Language: English
• Subjects: 631/443/319; 692/699/1702/393; 692/700/565; Absorptiometry, Photon; Adult; Analysis of Variance; Basal Metabolism; Biological and medical sciences; Body Composition; Body Mass Index; Calorimetry; Calorimetry, Indirect; Care and treatment; Deuterium; Diet; Diet, Reducing; Energy; Energy balance; Energy Intake; Energy Metabolism; Epidemiology; Exercise; Female; Health aspects; Health Promotion and Disease Prevention; Humans; Internal Medicine; Intervention; Male; Medical sciences; Medicine; Medicine & Public Health; Metabolic Diseases; Metabolism; Nutrition research; Obesity; Obesity - metabolism; Obesity - therapy; original-article; Patient Compliance; Physical fitness; Physical training; Physiological aspects; Physiology; Predictive Value of Tests; Public Health; Thermogenesis; Treatment Failure; Weight control; Weight Loss; Women
• ISSN: 0307-0565; 1476-5497
• DOI: 10.1038/ijo.2012.109

Objective: We investigated to what extent changes in metabolic rate and composition of weight loss explained the less-than-expected weight loss in obese men and women during a diet-plus-exercise intervention. Design: In all, 16 obese men and women (41±9 years; body mass index (BMI) 39±6 kg m −2 ) were investigated in energy balance before, after and twice during a 12-week very-low-energy diet(565–650 kcal per day) plus exercise (aerobic plus resistance training) intervention. The relative energy deficit (EDef) from baseline requirements was severe (74%–87%). Body composition was measured by deuterium dilution and dual energy X-ray absorptiometry, and resting metabolic rate (RMR) was measured by indirect calorimetry. Fat mass (FM) and fat-free mass (FFM) were converted into energy equivalents using constants 9.45 kcal per g FM and 1.13 kcal per g FFM. Predicted weight loss was calculated from the EDef using the ′7700 kcal kg −1 rule′. Results: Changes in weight (−18.6±5.0 kg), FM (−15.5±4.3 kg) and FFM (−3.1±1.9 kg) did not differ between genders. Measured weight loss was on average 67% of the predicted value, but ranged from 39% to 94%. Relative EDef was correlated with the decrease in RMR ( R =0.70, P