Interpretation of Appropriate Range of Body Mass Index and Body Weight Management Standards for the Oldest Old: Evidence-based Recommendations from China

With the rapid aging of China's population, the number of adults aged ≥ 80 years is rising, and their nutritional status and weight management have attracted growing attention. Body mass index (BMI) is a commonly used indicator for assessing body weight and nutritional status. However, existing BMI standards were mainly developed for the general adult population, and their applicability to the oldest old population remains uncertain. To provide guidance for BMI evaluation and weight management among the oldest old population in China, the National Health Commission issued the standard " Appropriate body mass index range and weight management standards for the oldest old (WS/T 868-2025)". Based on evidence from prospective cohort studies including the Chinese Longitudinal Healthy Longevity Survey and the Healthy Aging and Biomarkers Cohort Study, the standard recommends an appropriate BMI range of 22.0-26.9 kg/m ² for adults aged ≥ 80 years and provides recommendations regarding BMI measurement, weight monitoring, and individualized weight management. The implementation of this standard provides scientific evidence for weight evaluation and health management in the oldest old population and contributes to promoting healthy aging.