The Study
Effect of diet‐induced weight loss on muscle strength in adults with overweight or obesity – a systematic review and meta‐analysis of clinical trials
This study looked at many smaller studies and found that when people lose weight by eating less, their muscles sometimes get weaker — especially in their legs. But it doesn't prove that eating less caused the weakness, because the original studies weren't done in a way that rules out other reasons.
Analysis score
Maximum 85 for a systematic review with meta-analysis.
Where the score came from
When people with extra weight lose weight by eating less, their muscles sometimes get weaker — especially the big muscles in their thighs.
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 539 / 100
Quality score
Systematic reviews and meta-analyses of cohort studies. They sit above a single cohort study but below a single randomized trial, because the underlying evidence is still observational.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Losing weight is still good for health, but this means people might feel weaker in daily activities like climbing stairs or carrying things — especially if they don't do strength training.
- 2Thigh strength dropped by 7.5%.
- 3Hand strength didn't change much overall, but dropped by 4.6% when people ate much less (but not when they ate very little food-restricted diets).
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Obesity Reviews
Year
2016
Authors
J. Zibellini, R. Seimon, C. Lee, A. Gibson, M. Hsu, A. Sainsbury
Related Content
Claims (6)
People with moderate body fat can lose fat while keeping their muscle mass unchanged.
In adults with overweight or obesity, losing weight through dieting is linked to a small overall drop in handgrip strength, but a larger drop in those who reduce calories moderately.
Adults with overweight or obesity who lose weight through dieting experience a 7.5% decrease in knee extensor strength, as measured by isokinetic dynamometry.
When people lose weight through dieting, their knee extensor strength consistently decreases, while handgrip strength changes unpredictably, showing that muscles in the legs are more likely to lose strength than muscles in the hands.
When adults with overweight or obesity lose weight through dieting, their muscle strength, especially in the legs, decreases.
During weight loss, people who reduce their calorie intake moderately lose upper body strength, while those on very low-calorie diets do not lose upper body strength.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.