Weight Loss Attempts Increased in Korean Adults from 2005 to 2021, Excluding Those with Obesity.

Background: Studies on trends in the proportions of past-year weight loss attempts among Asian adults are limited. Our hypotheses were that trends in the proportions would increase and sociodemographic, weight, and health-related factors would be associated with these attempts. Methods: Using data from the Korea National Health and Nutrition Examination Survey 2005-2021, this study evaluated the trends and their related factors among Korean adults. Complex sample design analyses were applied to the data of 80,160 adults. Results: The weighted proportion of past-year weight loss attempts increased from 35.2% in 2005 to 41.3% in 2021. The proportion of past-year weight loss attempts increased for individuals with nonobese body mass index (BMIs) (<25 kg/m2), decreased for males with obese BMIs (≥25 kg/m2), and did not change for females with obese BMIs. A multivariate-adjusted model showed that the proportion of weight loss attempts decreased for males and increased for females over the 16-year period [odds ratio (OR) (95% confidence interval): males, 0.993 (0.988-0.998); females, 1.013 (1.009-1.017)]. The OR of weight loss attempts was higher for females, younger individuals, and those with higher economic status, higher BMIs, self-perceived larger body shapes, self-rated better health, and chronic diseases. These characteristics decreased the odds of individuals with obese BMIs making no weight loss attempts. Conclusions: The proportion of past-year weight loss attempts increased over the 16-year period among all participants, but a declining trend was observed for those with obesity. In addition to BMI, socioeconomic factors, subjective perceptions of body shape, and health-related factors were related to weight loss attempts.