Trends in healthy weight prevalence among adults in Chongqing, China， 2013-2023: Findings from 4 consecutive representative cross-sectional surveys

Background Healthy weight—meeting both normal BMI and waist-circumference thresholds—is a sentinel marker of cardiometabolic risk. Despite escalating obesity and NCD burdens globally and in China, population-based evidence tracking decade-long trends in healthy weight and their relationship with major NCDs remains limited. Methods and findings We analyzed four waves of the Chongqing CCDRFS (2013, 2015, 2018, 2023) using complex survey weighting to estimate prevalences and linear trends by sex, residence, and age; multivariable survey-logistic models evaluated associations with NCDs and trends within hypertension/diabetes management strata. Healthy-weight prevalence decreased from 47.8% (95% CI: 44.5–51.0) to 40.1% (95% CI: 35.0–45.2; p for trend <0.05), with significant declines in men, rural residents, and adults aged 45–65 years; changes were not important in women, urban residents, or those aged 18-45 or≥65 years. BMI overweight/obesity increased from 39.9% (95% CI: 36.8–43.0) to 49.4% (95% CI: 44.0–54.8; p for trend <0.05), whereas central obesity changed from 29.4% (95% CI: 26.4–32.5) to 31.6% (95% CI: 27.2–35.9; p for trend =0.16) overall but rose in urban and older strata. Among adults with ≥1 NCD, healthy weight declined from 37.7% to 30.7% (p for trend <0.05) while BMI overweight/obesity increased from 50.9% to 59.4% (p for trend <0.05); central-obesity trends varied by condition. In adjusted analyses, healthy weight was associated with lower odds of ≥1 NCD (OR 0.34, 95% CI: 0.29–0.40), whereas BMI and central adiposity were associated with higher odds (e.g., BMI fat OR 3.72; central fat OR 3.83); patterns were consistent across hypertension, diabetes, dyslipidemia, and cardiovascular disease. Within hypertension/diabetes management strata, declines in healthy weight were attenuated and not statistically significant compared with the overall trend. Conclusions From 2013 to 2023 in Chongqing, healthy weight eroded while BMI-defined adiposity worsened, and central obesity concentrated in urban and older groups. Healthy weight was inversely related to NCDs, whereas BMI and central adiposity were positively related, underscoring the need to integrate weight management into chronic-disease programs and to prioritize men, rural residents, and older adults for targeted interventions.