• Higher overall, animal-based, and plant-based Chinese Healthy Eating Index scores are significantly associated with lower risk of low skeletal muscle mass in older Chinese adults.
• The protective association is more pronounced in females, with up to 43% risk reduction, while no significant association was observed in males.
• This study validates the Chinese Healthy Eating Index as a useful tool for assessing dietary quality and its link to muscle health in the Chinese population.
• Improving overall dietary quality, particularly balanced intake of plant and animal foods, may serve as a public health strategy to prevent muscle loss in the elderly.