Macrorelationship between average life expectancy and prevalence of obesity: Theory and evidence from global data

A large body of literature assesses the impact of obesity on health at the microlevel and finds that obesity is a risk to health and longevity of life. We develop a macrolevel analytical framework to investigate the impact of obesity prevalence on average life expectancy, the trade-off between health expenditure and obesity prevalence, and the differential effect of obesity prevalence by gender, and apply this framework to cross country national data using a panel data of 183 countries for the years 2007 to 2014. The empirical analysis shows that the average life expectancy is a concave function of obesity prevalence, and an increase in obesity prevalence increases average expected life expectancy with low obesity levels. While obesity is a significant problem in developed countries, its impact on average life expectancy is partially mitigated by health expenditure. Underweight and lack of health expenditure in developing countries are even more severe problems. The marginal benefit of health expenditure in a low obesity country (highly correlated with underweight) has a larger impact on life expectancy relative to that in a high obesity country. A part of the longer life expectancy of women is related to better average nutritional state and less vulnerability to obesity. The results are consistent over three macromeasures of the longevity of life-average life expectancy, adult mortality rate, and healthy life expectancy.