Research

Energy balance

Sustained moderate-intensity exercise (approx. 2000 kcal/week) prevents weight gain in young overweight women but produces significant fat loss in young overweight men over 16 months, independent of dietary changes.

If you are young and overweight, committing to about 45 minutes of moderate exercise (like brisk walking or cycling) five days a week will likely keep you from gaining weight. Men in this study actually lost significant fat, while women maintained their weight while sedentary controls gained. Do not expect rapid weight loss if you do not change your diet, but expect significant long-term health and composition benefits compared to doing nothing.

GoodQualifiesHIGH confidence
Exercise prevented weight gain in women and produced weight loss in men... Men in the exercise group had significant mean±SD decreases in weight (5.2±4.7 kg)... and fat mass (4.9± 4.4 kg) compared with controls. Women in the exercise group maintained baseline weight... and controls showed significant mean±SD increases in body mass index (1.1±2.0), weight (2.9 ± 5.5 kg), and fat mass (2.1 ± 4.8 kg) at 16 months.
Joseph E. Donnelly et al. · PubMed · 2003

Why this rating

Randomized controlled trial with supervised exercise and objective measures (DLW, CT), though attrition was high (44%).

Source

Effects of a 16-month randomized controlled exercise trial on body weight and composition in young, overweight men and women: the Midwest Exercise Trial.

Joseph E. Donnelly et al. · PubMed · 2003

DOI 10.1001/archinte.163.11.1343

rct · n=131Cited 489×
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DOI resolved against Crossref · corpus check 2026-06-10

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