Because they worked off the fat, not being overweight, which is usually concomitant with the conditions the doctor cites. While a steady diet of most of these is not good, I think that a person who normally will "eat in due season for strength [when needed for energy, physiological hunger: vs. psychological or hedonic hunger], and not for drunkenness [intoxication]" (Ecclesiastes 10:17) and only as much as needed for energy, and includes healthy foods but also some of the forbidden ones, would normally be healthier and live longer , by the grace of God - other factors being equal - than one who only eats "healthy" but to excess.