The study examined the association between eating frequency and low muscle mass in 6,427 middle-aged and older Koreans from the KoGES cohort. Participants were divided into low frequency (1–2 meals per day) and high frequency (3–5 meals per day) groups. Low muscle mass was defined as a muscle mass index (MMI, kg/m²) below the sex-specific 20th percentile. Higher eating frequency was independently associated with lower odds of low muscle mass (OR = 0.685, 95% CI: 0.1828, p < 0.001 overall), even after adjustment for age, sex, BMI, protein intake and physical activity. This finding held true regardless of total protein intake. The study highlights meal frequency as a potentially important nutritional factor for maintaining muscle mass. This is a cross-sectional design that offers new insights from a large cohort.