Macro partitioning
GLP-1 based therapies (Retatrutide, Ebenatide) cause significant muscle mass loss at higher doses, whereas lower doses or standard GLP-1 agonists preserve muscle mass better.
If you are using high-dose GLP-1 based therapies (like Retatrutide 8-12mg), be aware that you may lose more muscle than with lower doses or standard GLP-1s. This is a trade-off for greater fat loss. Prioritize protein intake and resistance training to protect your muscle mass, especially if you are older.
Retatrutide at 8 and 12 mg significantly reduced body weight, total fat mass, and muscle mass at 36 weeks (p < 0.0001)... Ebenatide at 2 mg promoted weight loss... Body fat decreased at 24 weeks with preserved muscle mass. However, muscle mass declined slightly by 52 weeks.
Why this rating
Based on only 2 recent RCTs, analyzed separately due to limited data.
Source
The Effects of <scp>SGLT</scp> 2 Inhibitors on Muscle Health in Older Adults: A Systematic Review and Meta‐Analysis
Weena Joongpan et al. · Pharmacology Research & Perspectives · 2026
DOI 10.1002/prp2.70232
Related findings · Macro partitioning
- Total daily protein intake of 1.6 g/kg/day is sufficient for maximizing resistance training-induced muscle gains, with an upper confidence interval of 2.2 g/kg/day.Strong
- Resistance exercise training combined with sufficient dietary protein intake acts synergistically to maximize skeletal muscle hypertrophy, with protein intake saturating around 1.6 g/kg/day for general populations and potentially requiring 2.0-2.2 g/kg/day for resistance-trained individuals.Strong
- Trans fats should be completely eliminated from the diet, as they increase LDL cholesterol, decrease HDL cholesterol, and are directly associated with increased coronary risk.Strong
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