This really depends how you calculate cost to society. Everyone dies, and the healthiest people die the slowest. So when you look at the cost of the alternatives the difference looks much smaller or non-existant. If the alternative of getting a heart attack at 57 is retiring at 67, collecting social security for 20 years, getting Alzheimers at 73 and spending 10 years in a Medicare funded memory care facility, obesity and alcoholism don't look as expensive.