Body mass index and self-rated health in East Asian countries: Comparison among South Korea, China, Japan, and Taiwan.

There have been conflicting findings regarding the relationship between body mass index (BMI) and self-rated health (SRH) worldwide. The purpose of this study was to examine the association between BMI and SRH by comparing its relationship in four East Asian countries: South Korea, China, Japan, and Taiwan. Using data from the East Asian Social Survey, the relationship between weight status and SRH status was investigated and compared between four countries, China, Japan, South Korea, and Taiwan. An ordinal logit regression model was estimated for each country, and the results were compared. We found that the relationship between weight status and SRH status differed across the four countries. In China, people who were overweight reported better SRH scores than those of normal weight, whereas in Japan, obese and severely obese people reported poor scores. In contrast, South Koreans who were underweight, obese, or severely obese reported poor ratings of health status than those of normal weight. In Taiwan, however, no differences in respondents' weight status were found across SRH scores. There were notable differences in the relationship between BMI and SRH status in four East Asian countries. Individual countries should consider these relationships when designing and implementing obesity intervention programs.