A Muscle-Centric Perspective on Intermittent Fasting: A Suboptimal Dietary Strategy for Supporting Muscle Protein Remodeling and Muscle Mass?
Level 5 - mechanism / opinion, no new human data
Narrative commentary and mechanism-based reasoning without new primary empirical data
PubMed 34179054 · doi:10.3389/fnut.2021.640621
What was done
This narrative commentary evaluated the physiological mechanisms governing skeletal muscle protein turnover—specifically muscle protein synthesis and breakdown across fasted and fed states—to assess the theoretical impact of intermittent fasting regimens on lean mass retention and muscle remodeling.
What was found
The abstract reports no original experimental data or quantitative results. Mechanistically, the authors argue that infrequent feeding and prolonged fasting fail to optimize muscle protein turnover because muscle protein synthesis is saturable and requires distributed dietary amino acid intake, alongside the anti-catabolic actions of insulin.
Why it matters
It provides a mechanistic counterpoint to the popularity of intermittent fasting, suggesting that prolonged fasting intervals may compromise muscle remodeling and lean mass retention, particularly during caloric restriction.
Limits
This is a theoretical commentary rather than an empirical trial or systematic review. It presents no new human data, sample size, or direct clinical measurements of muscle mass changes under fasting conditions.
Cited by
- supports Fasting causes muscle breakdown rather than muscle building.