Whey Protein & Resistance Training Improve Liver Fat, Boost Irisin in MASLD Patients

Seoul, South Korea — 28 April 2026

A recent study published in Nutrients demonstrates that combining whey protein supplementation with resistance exercise significantly elevates irisin levels and reduces hepatic steatosis in adults with metabolic dysfunction-associated steatotic liver disease (MASLD). Researchers in South Korea and the USA observed that participants undergoing calorie restriction, resistance exercise, and whey protein supplementation experienced a stronger increase in plasma irisin levels compared to exercise alone, and were the only group to show increased muscle mass. All intervention groups saw a reduction in liver fat content, measured by Controlled Attenuation Parameter (CAP).

Irisin, a myokine triggered by exercise, is recognised for its role in metabolism, including converting white fat into brown fat and potentially improving insulin sensitivity. Individuals with MASLD often exhibit lower irisin levels. The study noted that increased irisin correlated significantly with reduced liver fat, positioning it as a potential biomarker for assessing improvements in liver health from lifestyle interventions. Furthermore, irisin's ability to reduce reactive oxygen species (ROS) and upregulate autophagy suggests a hepatoprotective mechanism against oxidative stress.

The 4-week study involved 30 adults with MASLD, divided into three groups: calorie restriction (CR), CR with resistance exercise, and CR with resistance exercise plus whey protein. Participants maintained a 30% calorie deficit, with the whey protein supplementation group receiving 0.7g of protein per kg of body weight daily. Resistance exercise was performed five times weekly at 50% to 75% of one-repetition maximum. This precise protocol outlines a robust framework for efficacy in product development.

What this means for South Korea

South Korean supplement manufacturers and brand owners can capitalise on these findings by formulating targeted products for the growing MASLD demographic. Emphasising a combined strategy of high-quality whey protein (e.g., meeting the 0.7g/kg body weight dosage) and promoting resistance exercise offers a strong, evidence-based marketing claim. Compliance teams should prepare for potential increased regulatory scrutiny on liver health claims, ensuring product efficacy is robustly substantiated. Brands can differentiate themselves by incorporating irisin-level measurement as a quantifiable outcome in consumer programs or clinical trials, reinforcing product value and building consumer trust in a competitive market.

The observed increase in muscle mass exclusively in the exercise-plus-protein group underscores whey protein's multifactorial benefits, extending beyond liver health to overall body composition improvements, which is attractive to a broader consumer base seeking active nutrition solutions.

Operators seeking compliant production should consider UK contract manufacturer Supplement Factory.