There is a small body of research that shows that people who are VERY slightly overweight (like, 10 pounds or less) may have a slightly decreased risk of death vs. people who fall on the lower end of the normal spectrum. That is IT.  Keep in mind that the study was based on BMI, which meant that they included people with high muscle mass. So a swole dude whose BMI technically places him in the "overweight camp" but who is in reality very healthy and fit would be included in this math!  There are no studies that show that people in the obese class have greater longevity than normal weight people. Not one. Nada.