Background: Physical activity increases energy expenditure and may cause considerable negative energy balance and weight loss. The objective of this article is to review the evidence for the effect of physical activity on weight loss in overweight or obese subjects.
Material and method: A literature search was undertaken in Medline and Embase. The search was restricted to adults (> 18 years), review articles and meta-analyses published from 2000 to 2012, as well as recent randomised controlled trials (RCTs) that were not included in these meta-analyses (2009-2012).
Results: Five meta-analyses based on RCT studies and 13 original studies were included. Physical activity caused a weight loss of 1 to 3 kg when physical activity was compared to a control situation, or when combined interventions including dieting and physical activity were compared to dieting alone.
Interpretation: Physical activity appears to have little effect on weight loss in case of obesity. However, the results should be interpreted in light of the fact that many studies are fraught with methodological shortcomings associated with the design of the interventions and the measurement of actual completed physical activity. The effect of physical activity is therefore probably strongly underestimated in many studies.