Objective This research focused on examining the distinctive characteristics of nutrient intake and dietary patterns among long-lived elderly individuals. Additionally， the study was aimed to explore the specific dietary components that may impact the skeletal muscle mass in this particular group.

Methods This study was conducted in the Chongming area of Shanghai， China. A total of 206 long-lived elderly individuals aged 90 or above were recruited. The 3-day 24-hour dietary recall method was used to collect dietary information and general demographic data through face-to-face interviews with professional nutritionists. The skeletal muscle mass index（SMI） was measured by bioelectrical impedance analysis（BIA）， and low skeletal muscle mass was diagnosed based on the 2019 Asian Working Group for Sarcopenia criteria. T-test analysis， chi-square test， and logistic regression were used to analyze the relationship between dietary nutrient intake and skeletal muscle mass.

Results In terms of food intake categories， compared with the long-lived elderly people with normal muscle mass， the intake of cereals containing miscellaneous beans and vegetables in the long-lived elderly people with low muscle mass was significantly lower （P<0.05）. In terms of the nutrient intake， compared with the long-lived elderly people with normal muscle mass， the intake of total energy， carbohydrate， dietary fiber， vitamin D， folic acid， phosphorus， potassium， magnesium， iron， and manganese in the long-lived elderly people with low muscle mass was significantly lower（P<0.05）. After continuous adjustment for the covariates， multivariate logistic regression analysis found that the intake levels of folic acid and dietary fiber were important factors influencing skeletal muscle mass， Individuals with lower intake levels of folic acid and dietary fiber are at a higher risk of low muscle mass in long-lived elderly individuals ［OR_{folic acid T1}，_{dietary fiber T1} （95%CI）： 2.90 （1.11‒7.61）； 4.09 （1.53‒10.91）］.

Conclusion The consumption of cereals that include a variety of beans and vegetables was noticeably lower in the long-lived elderly individuals with lower muscle mass when compared to those with normal muscle mass. Furthermore， low levels of folic acid and dietary fiber intake are associated with an increased risk of low skeletal muscle mass.