Macro partitioning
In older women, substituting total or animal protein with fat or carbohydrates is negatively associated with appendicular skeletal muscle mass (ASMM) in cross-sectional analyses, but this association disappears in longitudinal analyses over 20 years.
For older women, simply eating more protein than fat or carbs might not protect muscle mass in the long run (20 years). While cross-sectional data shows a link between lower protein and lower muscle mass, long-term tracking shows no clear benefit. Focus on overall diet quality and physical activity rather than just maximizing protein intake.
Adjusted, multivariate linear regression analyses revealed a negative cross-sectional association between the substitution of total protein (TP) and animal protein (AP), with fat and carbohydrates, on ASMM in women but not in men. No longitudinal associations were found between substitution of dietary protein intake and ASMM in either sex in adjusted models.
Why this rating
Observational cohort study with long follow-up (20 years) and large sample size (n=2060), but relies on FFQs and cannot prove causation.
Source
The Association of Isocaloric Substitution of Dietary Protein in Middle Age with Muscle Mass and Strength in Old Age: The Hordaland Health Study
Zoya Sabir et al. · Current Developments in Nutrition · 2023
DOI 10.1016/j.cdnut.2023.102052
Related findings · Macro partitioning
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