Life expectancy for men in America is 76.4 years old. Add to that factor, extra weight or obesity, and the number goes down. Maybe Trump has one term in him before he has issues with his health in general, but it wouldn't be a surprise if he didn't either.
Keep in mind that that mean life expectancy also factors in people who die prematurely (homicides, suicides, accidents, etc.) Mean life expectancy for those who make it to senior citizenship is, from what I understand it, in the low 80s—but you also have to take into account that the last nine years, on average, of an elderly person's life is spent in poor health.
Now, Fred Trump (Don's father) lived to be 93. I don't know how well he aged, but Donald doesn't appear to be aging much better than Hillary Clinton is. Compare him 20 years ago with what he looks like now. Compare him even 10, maybe even 5. They're trying to make him look as youthful as they can, but there's only so much airbrushing they can do. He's looking ragged.
