Ketogenic diet induces metabolic remodeling and alters myogenic markers in skeletal muscle of obese male mice with knee injury
In obese male mice subjected to medial meniscus destabilization, switching to a ketogenic diet for eight weeks promoted weight loss, raised circulating β‑hydroxybutyrate, and triggered a transcriptional shift in gastrocnemius muscle toward enhanced lipid oxidation. The diet also increased expression of satellite‑cell markers Pax7, Myf5 and MyoD1 without worsening motor performance.
Study and findings
Male C57BL/6J mice were rendered obese by high‑fat feeding and then underwent surgical destabilization of the medial meniscus, a model that combines metabolic overload with joint injury. After surgery the animals continued on the high‑fat diet (HFD) or were switched to either a standard chow diet (CD) or a ketogenic diet (KD) for eight weeks. KD produced significant weight loss, lowered blood glucose, and raised plasma β‑hydroxybutyrate, yet absolute gastrocnemius mass and motor performance remained stable. Molecular analysis of the gastrocnemius revealed up‑regulation of Acat1 and a transcriptional program indicative of increased capacity for lipid‑derived substrate utilization, including higher Ppargc1a, Acadl, Cpt1b and Pdk4 expression. Targeted serum metabolomics showed selective remodeling of long‑chain and hydroxy‑acylcarnitine species, consistent with altered systemic lipid handling. Importantly, KD also elevated the myogenic‑associated genes Pax7, Myf5 and MyoD1, suggesting a shift in satellite‑cell activity.
Clinical interpretation
The findings demonstrate that, in the context of obesity and joint injury, a ketogenic dietary regimen can drive skeletal‑muscle metabolic adaptation toward greater fatty‑acid oxidation without compromising muscle mass or functional output. The up‑regulation of Ppargc1a and related oxidative genes aligns with a shift to an endurance‑type phenotype, which may be advantageous when energy substrates are limited. The concurrent increase in Pax7, Myf5 and MyoD1 hints that KD may influence satellite‑cell activation or differentiation, a process relevant to muscle repair after injury. However, because the study was performed in mice, extrapolation to human patients with osteoarthritis or sarcopenia must be cautious.
Limitations and open questions
The experiment used a single sex, strain and injury model, limiting generalizability across sexes, species and types of joint pathology. The duration was eight weeks; longer‑term effects on muscle quality, tendon integrity, and joint health remain unknown. Functional assessments were limited to motor performance tests, without detailed evaluation of muscle strength or endurance. Finally, the study did not compare KD to a calorie‑matched low‑carbohydrate control, so the observed effects cannot be isolated from overall energy deficit.
Source
PMID: 42854762; DOI: 10.1016/j.jnutbio.2026.110515.