The Study
Effects of Calorie Restriction With and Without Strength, Endurance or Mixed Training on Fat-Free and Skeletal Muscle Mass in Overweight or Obese Individuals-A Systematic Review With Pairwise Meta-Analysis and Network Meta-Analysis of Randomized Controlled Studies.
This study looked at lots of experiments where people tried losing weight with diet alone or diet plus exercise. It found that adding exercise helps keep more muscle when you're dieting — but it doesn't prove exercise is the only reason, because some studies might not have been reported. Think of it like checking many reports to see if wearing a helmet helps avoid head bumps — it looks like it does, but we can't be 100% sure.
Analysis score
Maximum 100 for a systematic review with meta-analysis.
Where the score came from
When you eat less to lose weight, you also lose muscle. But adding exercise—especially lifting weights or mixing strength and cardio—helps you keep more muscle.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 577 / 100
Quality score
The highest quality evidence. Systematic reviews and meta-analyses that pool randomized controlled trials, giving the most reliable summary of experimental evidence.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Losing muscle makes you weaker and slows your metabolism.
- 2Keeping even 1 kg more muscle helps you stay strong, burn more calories, and avoid frailty.
- 3Lifting weights keeps 0.83 kg more muscle than dieting alone.
- 4Mixing strength and cardio keeps 1.20 kg more.
- 5Just doing cardio keeps 0.51 kg more—but that wasn’t strong enough to be sure.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Diabetes, obesity & metabolism
Year
2026
Authors
Magdalena Deller, Jan Weiershaus, Steffen Held, C. Brinkmann
Related Content
Claims (6)
When overweight or obese adults cut calories and add structured exercise, they lose 0.87 kilograms less lean tissue than when they cut calories alone.
In overweight or obese adults, combining strength and endurance exercise preserves 1.20 kilograms more fat-free mass than calorie restriction alone, and this difference is the largest among all exercise types studied.
In overweight or obese adults, strength training results in 0.83 kilograms more preservation of fat-free mass compared to calorie restriction alone.
In overweight or obese adults, endurance training results in 0.51 kg more fat-free mass retention compared to calorie restriction alone, but this difference is not statistically significant, and resistance training preserves more fat-free mass than endurance training.
In overweight or obese adults, adding exercise to a calorie-restricted diet reduces the loss of lean body mass by about 45.7% compared to dieting without exercise.
When people reduce their calorie intake, their total body weight changes similarly whether or not they do resistance training.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.