Weight change and mental health according to obesity in relatively healthy middle-aged Korean women: The Korea National Health and Nutrition Examination Survey 2014, 2016, 2018

•Weight change in both non-obese and obese women was associated with poorer mental health, including perceived stress and depressed mood, although the significance disappeared in covariates-adjusted analysis in obese women.•Both non-obese and obese women with weight gain had higher perceived stress than women with weight loss, while in the PHQ-9 scores higher scores were observed in non-obese women with weight gain, and in obese women with weight loss.•Current depressive disorder was associated with weight gain in non-obese women, but not in obese women.•Rather than obesity, weight change was a significant factor associated with mental health in relatively healthy middle-aged Korean women. Obesity is a known risk factor for various chronic conditions, as well as mental health disorders. However, there have been few studies on weight change and mental health according to obesity. This study was performed to elucidate the association between weight changes and mental health according to obesity in middle-aged women. Data from the Korean National Health and Nutrition Examination Survey (2014, 2016, 2018), which included 3953 women aged 40 to 59, were used in this study. After excluding those who had chronic conditions possibly affecting weight change, 2964 women were included in the study. The associations between weight changes and mental health, including perceived stress, depressed mood surveyed by the patient health questionnaire-9(PHQ-9), and current depressive disorder were analyzed. Weight change in non-obese and obese women was associated with poorer mental health, including perceived stress and depressed mood (p