The Study
Effects of Adherence to a Higher Protein Diet on Weight Loss, Markers of Health, and Functional Capacity in Older Women Participating in a Resistance-Based Exercise Program
This study is like a fair race between three groups of older women: one group just exercised, one ate more carbs, and one ate more protein. The protein group lost more fat, but we don’t know if it was because of the protein or because they tried harder. So we can say protein 'probably helped,' but we can’t say it 'caused' the weight loss for sure.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Older women who lifted weights and ate more protein lost more fat than those who just lifted weights or ate more carbs.
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 569 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Losing 10% body fat is clinically meaningful and helps reduce disease risk — and keeping muscle and metabolism stable is rare with dieting, making this result especially valuable for older adults.
- 2Women who ate 1.28g protein per kg of body weight lost 10.2% fat mass and 6.3% body fat, while those on carbs lost 5.9% and 4.3%, and those who only exercised lost 2.7% and 2.0%.
- 3All groups got stronger and more balanced.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Nutrients
Year
2018
Authors
M. Galbreath, B. Campbell, P. LaBounty, J. Bunn, J. Dove, T. Harvey, G. Hudson, Jean L. Gutierrez, K. Levers, E. Galvan, A. Jagim, L. Greenwood, M. Cooke, M. Greenwood, C. Rasmussen, R. Kreider
Related Content
Claims (6)
Resistance training increases the effectiveness of dietary protein in preserving muscle mass and supporting physical function.
In overweight and obese women aged 60–75, consuming a higher protein diet during resistance training raised adiponectin levels by 52.4% and lowered leptin levels by 26.5%, while a higher-carbohydrate diet lowered adiponectin by 27.9% and raised leptin by 43.8%.
Among overweight and obese women aged 60 to 75, a 14-week program of supervised resistance training and a higher protein diet led to greater reductions in body fat and body fat percentage than a higher-carbohydrate diet or exercise alone, without loss of muscle mass or resting energy expenditure.
In overweight and obese women aged 60 to 75, a 14-week resistance training program increases muscular strength, endurance, aerobic capacity, and balance without requiring changes to diet.
Among overweight and obese women aged 60 to 75, consuming more protein while doing resistance training does not lead to greater gains in muscle strength, endurance, or aerobic fitness compared to doing resistance training alone or with a higher-carbohydrate diet.
In overweight and obese women aged 60–75, consuming 1.28 grams of protein per kilogram of body weight per day during resistance training does not lower resting energy expenditure, whereas higher protein diets typically lower resting energy expenditure during weight loss.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.