An Imperial College researcher with colleagues in Iran has found dose-response effects of aerobic exercise in measures of overweight and obese adults. Clinically significant improvements were observed in individuals who performed moderate to vigorous aerobic exercise at least 150 minutes per week.

Global obesity prevalence has tripled in the past 45 years, leading to more than 50% of adults worldwide being overweight or obese. Obesity has the highest death-related disease risk, according to the 2019 Global Burden of Disease Study.

Current guidelines recommend aerobic exercise as a key component of weight management, with 150 minutes per week often cited as the minimum threshold for meaningful weight loss.

These recommendations rely heavily on individual trials, and the researchers wanted to test whether a robust meta-analytic assessment of the dose-response relationship between aerobic exercise and body fat reduction would show similar results.

In the study “Aerobic Exercise and Weight Loss in Adults: A Systematic Review and Dose-Response Meta-Analysis,” published in JAMA Network Open116 randomized clinical trials involving 6,880 participants were analyzed.

Review studies included randomized clinical trials with durations of at least eight weeks focusing on supervised aerobic training for adults with overweight or obesity. A total of 116 trials comprising 6,880 participants (61% female, mean age 46 years) met the inclusion criteria.

The study found that for each 30-minute weekly increment of aerobic exercise, there was an associated reduction in mean body weight (-0.52 kg), waist circumference (-0.56 cm), and body fat percentage (-0.37%).

Exercise duration of 150 minutes per week correlated with clinically significant reductions in weight (-2.79 kg), waist circumference (-3.26 cm) and body fat percentage (-2.08%).

The effect on weight loss was linear, with still greater reductions observed at 300 minutes per week for weight (-4.19 kg), waist (-4.12) and body fat (-1.78).

Results show a linear reduction in body weight, waist circumference, and fat measures associated with increasing aerobic exercise duration with incremental benefits of longer exercise durations.

The findings reinforce current guidelines that 150 minutes per week of moderate-intensity or greater aerobic exercise may be necessary for clinically important improvements in waist circumference and body fat.

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