President Trump appears remarkably healthy for a 71-year-old man who doesn't eat well or exercise, and he aced a rudimentary cognitive ability test (you can take it yourself here), according to Dr. Ronny Jackson, the White House doctor appointed by former President Barack Obama in 2013. But not everyone is buying Jackson's assessment that Trump is 6-foot-3 and weighs 239 pounds, giving him a barely sub-obesity body mass index (BMI) of 29.9.