Predictors of Energy Compensation during Exercise Interventions: A Systematic Review

Abstract

Weight loss from exercise-induced energy deficits is usually less than expected. The objective of this systematic review was to investigate predictors of energy compensation, which is defined as body energy changes (fat mass and fat-free mass) over the total amount of exercise energy expenditure. A search was conducted in multiple databases without date limits. Of 4745 studies found, 61 were included in this systematic review with a total of 928 subjects. The overall mean energy compensation was 18% ± 93%. The analyses indicated that 48% of the variance of energy compensation is explained by the interaction between initial fat mass, age and duration of exercise interventions. Sex, frequency, intensity and dose of exercise energy expenditure were not significant predictors of energy compensation. The fitted model suggested that for a shorter study duration, lower energy compensation was observed in younger individuals with higher initial fat mass (FM). In contrast, higher energy compensation was noted for younger individuals with lower initial FM. From 25 weeks onward, energy compensation was no longer different for these predictors. For studies of longer duration (about 80 weeks), the energy compensation approached 84%. Lower energy compensation occurs with short-term exercise, and a much higher level of energy compensation accompanies long-term exercise interventions.

Keywords: body composition; energy compensation; exercise intervention.

Figure 1

Flow diagram of the screening process. From the 89 studies selected, 71 were from original studies and 18 were from secondary data analyses of the 71 papers that were included. From the 71 studies, 61 groups were used in the final analysis. For these 61 groups, results were presented for each sex (n = 26 male; n = 35 female), and body composition was measured with either dual-X-ray absorptiometry (DEXA), hydrostatic weighing or bod pod. Only articles with a mean age or with a small range of age (i.e., [19,20,21,22,23]) were kept for further investigation. One group was discarded because the frequency was not mentioned in the article.

Figure 2

Correlation between age and initial FM. The median of age = 31 years old; the median for initial FM in studies involving younger subjects = 20.8 kg; and the median for older subjects = 27.5 kg. There were n = 15 studies in all groups, except for the group of older subjects with a high initial FM (n = 16 studies).

Figure 3

Degree of energy compensation illustrated as the interaction between age and initial FM of individuals, as well as with the duration of each exercise intervention. Each exercise intervention study is represented by a symbol.