Author(s)

Adrienne S. Thomas, Jocelyn E. Holden, Jo Carol Chezem

Department of Educational Psychology, Ball State University, Muncie, USA.
Department of Family and Consumer Sciences, Ball State University, Muncie, USA..
Target Metabolism, Avon, USA.

The objective of this exploratory study was to describe changes in body composition and resting energy expenditure (REE) in adult women during weight reduction. A total of 69 client records were collected retrospectively from a 25 week commercial weight loss program that restricted calories to 90% of measured REE. Data analyzed included total body mass (TBM), fat mass (FM) and fat-free mass (FFM) from air displacement plethysmography; measured REE from indirect calorimetry; and predicted REE from linear regression. From baseline to week 25, there were significant declines in TBM (95.0 ± 24.1 kg to 87.2 ± 22.9 kg; P < 0.001) and FM (47.5 ± 18.5 kg to 39.9 ± 17.6 kg; P < 0.001). During the same time period, FFM remained unchanged (47.5 ± 7.3 kg to 47.2 ± 7.0 kg; P ≥ 0.05). REE was signify- cantly lower at weeks 13 (6595.2 ± 1312.1 kJ) and 25 (6608.2 ± 1404.6 kJ) compared to baseline (7117.4 ± 1471.5 kJ) (P < 0.001); however, REE at weeks 13 and 25 were similar (P ≥ 0.05). At weeks 13 and 25, predicted REE (6992.7 ± 1065.7 and 6939.2 ± 1056.0 kJ, respectively) was significantly higher than measured REE (6595.2 ± 1312.1 and 6608.2 ± 1404.6 kJ, respectively) (P < 0.001). The results of this study suggest that significant reduction in TBM is possible without the loss of FFM and that metabolic adaptation may occur during the process.

Energy Metabolism; Body Composition; Caloric Restriction; Weight Loss

A. Thomas, J. Holden and J. Chezem, "Body Composition and Energy Expenditure Changes during Weight Loss: An Exploratory Study," Food and Nutrition Sciences, Vol. 3 No. 2, 2012, pp. 153-156. doi: 10.4236/fns.2012.32023.