Assessment of Body Composition Change in a Community-Based Weight Management Program
Leslie A. Powell, MA, RD, David C. Nieman, DrPH, Chris Melby, DrPH, Kirk Cureton, PhD, Dan Schmidt, PhD, Edward T. Howley, PhD, James O. Hill, PhD, James R. Mault, MD, Heather Alexander, MS, RD, and Darby J. Stewart, PhD
Department of Health and Exercise Science, Appalachian State University, Boone, North Carolina (L.A.P., D.C.N.), Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, (C.M.), University of Colorado Health Sciences Center, Denver (J.O.H., J.R.M., H.A.), Colorado, Department of Exercise Science, University of Georgia, Athens, Georgia (K.C., D.J.S.), Department of Physical Education and Health Promotion, The University of Wisconsin-Oshkosh, Oshkosh, Wisconsin (D.S.), Department of Exercise Science and Sport Management, University of Tennessee, Knoxville, Tennessee (E.T.H.) [email@example.com]
Objective: The purpose of this study was to validate the use of the leg-to-leg bioelectrical impedance analysis (BIA) system in assessing change in body composition over 32 weeks in overweight and obese women participating in a community weight management program.
Design: Intervention, with subjects prescribed an energy-restriction diet and exercise program for 32 weeks and body composition measured pre-study and after 12 and 32 weeks.
Subjects and Setting: Overweight and obese premenopausal women (n=201) with no overt disease were recruited at six sites into community-based weight loss programs. One hundred and twenty-four women completed all aspects of the study.
Intervention: Energy intake was set at 0.8 x resting metabolic rate (RMR) for weeks 1 through 12, 1.0 x RMR for weeks 13 through 20 and 1.2 x RMR for weeks 21 through 32. Energy intake was based on a food exchange table, with the number of food exchanges adjusted to encourage a percent distribution of 55% carbohydrate, 30% fat and 15% protein. Subjects increased their daily walking distance by 3.2 km above pre-study levels.
Measures of Outcome: Underwater weighing, seven skinfolds, and leg-to-leg BIA tests were used to assess body composition.
Results: A 3 x 3 repeated measures ANOVA revealed no significant difference in detecting change in FFM at 12 and 32 weeks among underwater weighing, BIA and skinfold, (F(4,492)=1.73, p=0.141) (decrease in FFM of 1.0±3.3 kg, 1.7±2.2 kg, and 1.4±3.3 kg respectively, 32 weeks).
Conclusions: The leg-to-leg BIA system provides a valid measure of body composition change in overweight premenopausal women during a 32-week community-based weight loss program.