Effect of severe compared with moderate energy restriction on physical activity among postmenopausal female adults with obesity: a prespecified secondary analysis of the Type of Energy Manipulation for Promoting optimum metabolic health and body composition in Obesity (TEMPO) Diet randomized controlled Trial

Abstract

Background An under-explored strategy for increasing physical activity is the dietary treatment of obesity, but empirical evidence is lacking. Objectives To compare the effects of weight loss via severe versus moderate energy restriction on physical activity over 36 months. Methods 101 postmenopausal female adults (45–65 years, 30–40 kg/m2, <180 minutes per week of structured exercise) were randomized to either 12 months of moderate energy restriction (25–35% of energy requirement) with a food-based diet, or a severe intervention involving 4 months of severe energy restriction (65–75% of energy requirement) with a total meal replacement diet, followed by 8 months of moderate energy restriction. Physical activity was encouraged, but no tailored or supervised exercise prescription was provided. Physical activity was assessed with an accelerometer worn for 7 days prior to baseline (0 months) and 0.25, 1, 4, 6, 12, 24 and 36 months after intervention commencement. Results Compared to the moderate group, the severe group exhibited greater mean levels of: total volume of physical activity; duration of moderate-to-vigorous-intensity physical activity (MVPA); duration of light-intensity physical activity; and step counts, as well as lower mean duration of sedentary time. All these differences (except step counts) were apparent at 6 months (e.g., 1006 [95% confidence interval 564, 1449] MET-minutes per week for total volume of physical activity), and some were also apparent at 4 and/or 12 months. There were no differences between groups in the two other outcomes investigated (self-efficacy to regulate exercise; and proportion of participants meeting the World Health Organization's 2020 Physical Activity Guidelines for MVPA). When the analyses were adjusted for weight at each time point, the differences between groups were either attenuated or abolished. Conclusions Among female adults with obesity, including a dietary component to reduce excess body weight—notably one involving severe energy restriction—could potentially enhance the effectiveness of physical activity interventions.

Postmenopausal women's experiences of weight maintenance following a very low energy diet

“…Additionally, recent analysis of food diaries of participants of the TEMPO Diet Trial has shown that diet quality improved for all participants from baseline, and this was mostly driven by a reduction in the intake of discretionary foods 46 . The VLED intervention group also showed higher levels of physical activity and lower levels of sedentary behavior at 6 and 12 months, in comparison to the non‐VLED group 47 . Taken together, these factors likely contribute to the longer‐term successful weight loss that is seen in response to VLEDs.…”

“… 46 The VLED intervention group also showed higher levels of physical activity and lower levels of sedentary behavior at 6 and 12 months, in comparison to the non‐VLED group. 47 Taken together, these factors likely contribute to the longer‐term successful weight loss that is seen in response to VLEDs.…”