Effects of physical activity type and sedentary time on metabolically healthy obesity and metabolically unhealthy normal weight Korean men

Obesity has become a global health challenge linked to morbidity and mortality associated with cardiovascular diseases. This study aimed to compare metabolic health indicators according to obesity phenotypes and examine prevalence according to physical activity (PA) and sedentary time in metabolically healthy obesity (MHO) and metabolically unhealthy normal weight (MUNW). Data were obtained from 3242 men participating in the 7th and 8th Korean National Health and Nutrition Examination Surveys. Participants were divided into four groups based on body phenotype and metabolic health status using obesity. Metabolic health was defined as metabolic syndrome. Representative statistical analyzes were one-way analysis of variance (ANOVA) and multiple logistic regression analysis. Compared with MUNW, the MHO had higher obesity, but systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting glucose (FG), hemoglobin A1c (HbA1c), triglycerides (TG), low density lipoprotein cholesterol (LDLC), and total cholesterol (TC) were significantly lower. In comparison between MHO and metabolically healthy normal weight (MHNW), the same health group, there were no significant differences in SBP, FG, HbA1c, and LDLC. The odds ratio of MUNW in the normal weight group was 1.8 times higher than that of the high group in the low leisure PA group. The group with high sedentary time increased the MUNW odds ratio by 1.5 times compared to the low group. Meanwhile, in the obesity group, the high leisure PA group showed a 1.4-fold increase in the MHO odds ratio compared to the low group. In addition, the low sedentary group showed a 1.6-fold increase in the MHO odds ratio compared to the high sedentary group. In conclusion, MHO had higher adiposity than MUNW, but the metabolic health index was better. Low PA and high sedentary time increased the risk of MUNW even in normal weight. Conversely, high PA and low sedentary time increased the likelihood of MHO in the obesity group.