Macro partitioning
Increasing protein intake to 1.6 g/kg body weight via whole foods for 17 weeks, with or without strength training, does not adversely affect gastrointestinal microbiota composition, richness, or diversity in community-dwelling older adults.
If you are an older adult (65-85) looking to maintain muscle, you can safely increase your protein intake to about 1.6 grams per kilogram of body weight daily. This study used whole foods (dairy, meat, plant proteins) rather than powders, and combined this diet with strength training for the last 8 weeks of a 17-week period. The key takeaway is that this level of protein does not harm your gut bacteria or cause inflammation, provided you are generally healthy and not on antibiotics. Focus on diverse protein sources like milk, soups, and lean meats.
The findings suggest that increasing protein intake via food sources up to 1.6 g/kg body weight for more than 4 months, with or without strength training, does not adversely affect the GI microbiota composition in older adults.
Why this rating
Randomized controlled trial with a relatively large sample size (n=112) for this specific sub-analysis, though limited to a specific demographic (Vienna, 65-85).
Source
The impact of a high-protein diet with strength training on the gastrointestinal microbiota in community-dwelling older adults: subanalysis of a randomized controlled trial
Patrick A. Zöhrer et al. · Frontiers in Nutrition · 2026
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