Meta-analysis about the effect of caloric restriction on functionality

There is a concern that a reduction in energy intake would impairs physical performance and functionality in general. However, caloric restriction (CR), a dietary intervention
defined as a reduction in energy intake without nutrient deficiency, is able to improve a number of body functions and, thus, could be also able to improve physical functionality. We
ran a systematic review in November 2019 that led to inclusion of 9 studies. 15 subgroups were extracted for two main meta-analysis of CR effects on overall functionality: 1) Nonexercise meta-analysis, in which only CR effects were tested by comparison of CR without exercise (CR-NEX) and no diet without exercise (NEX); and 2) Exercise meta-analysis, in
which additional CR effects on exercise interventions were tested by comparison of CR plus exercise training (CR-EX) and exercise training (EX). The CR effects on functionality were
more evident when CR was the only intervention (SMD: 0.40 [CI95%: 0.015; 0.65], p <0.001), however, the addition of CR intervention for individuals undergoing exercise cause
a small but consistent extra improve on functionality (SMD: 0.12 [CI95%: 0.04; 0.19], p <0.001). Among the components of functionality, CR was significantly effective on Balance,
daily life endurance and mobility improvements (p<0.05), but not on agility, daily life strength, flexibility or vitality. Therefore, there is no reason for overweight or obese individuals
fear functionality loss with caloric restriction.