This chapter reports that the mortality penalty linked with obesity has been falling in recent decades. It describes how, in current data, the relationship between obesity and mortality is complex; although class II and III obesity are associated with elevated mortality risk, overweight and class I obesity are generally not associated with higher mortality. Studies that measure body mass index (BMI) when respondents are middle aged and model mortality into later life can give a better sense of the BMI and mortality relationship at the older ages. A high BMI is a small source of excess deaths...

This chapter reports that the mortality penalty linked with obesity has been falling in recent decades. It describes how, in current data, the relationship between obesity and mortality is complex; although class II and III obesity are associated with elevated mortality risk, overweight and class I obesity are generally not associated with higher mortality. Studies that measure body mass index (BMI) when respondents are middle aged and model mortality into later life can give a better sense of the BMI and mortality relationship at the older ages. A high BMI is a small source of excess deaths in the United States, although this topic continues to be controversial. Studies that measure BMI in middle age and model subsequent mortality may give a better sense of the effect of BMI on mortality for those over the age of 50.