It was learned from the First Affiliated Hospital of Chongqing Medical University that Professor Li Qifu's team of endocrinology department of the hospital discussed the causal relationship between fat content and death risk based on gene analysis. Research shows that there are "healthy thin" and "unhealthy thin" for people with low body fat content; But for people with too much fat, there is no "healthy obesity". Relevant research results were published in the international journal Metabolism. Based on a large sample cohort from the UK Biobank, the study used two different methods to assess the relationship between body fat content and mortality risk. The researchers first analyzed the relationship between fat content and death risk by combining genome-wide association study, polygenic risk score and Mendel randomization method. The results showed that there was a linear causal relationship between fat content and all-cause death, which showed that every 1kg/m2 of fat content increased, the death risk increased by 8%. Subsequently, the researchers used bioelectrical impedance to measure the fat content and analyze its relationship with the risk of death. The results showed that the fat content and the risk of death were non-linear, that is, too little or too much fat content increased the risk of death. The study suggests that the traditional fat content assessment method (bioelectrical impedance measurement) may be affected by confounding factors. Li Qifu's team further analyzed and found that lifestyle is an important confounding factor, which has seriously affected the relationship between fat content and death risk. That is, in people with healthy lifestyles, the relationship between fat content and all-cause death is linear, that is, the more fat content, the higher the death risk. In people with unhealthy lifestyles, too much or too little fat content will increase the death risk. (Outlook New Times)