9. Runners need to eat as carefully as non-runners.
Many runners assume they can “get away with” eating a little more junk than couch potatoes can. Sports nutrition experts frequently try to correct this assumption, arguing that saturated fat, sugar, and the rest have the same terrible effects on the body whether you run or not. Actually, the runners have it right. High-volume aerobic exercise does mitigate the negative effects of consuming certain nutrients that are generally labeled “bad”. The license to eat a little more garbage—and to just eat a little more period—is one of the great rewards of running.
That said, the diet of the average American is awful, and running definitely does not give you license to eat even worse than that with impunity. Couch potatoes need to eat an almost perfectly clean diet to maintain a modicum of health, and even that is not enough, as robust health is impossible without exercise. What you as a runner can get away with is eating a diet that’s a little worse than the perfect diet that’s a must for the non-runner.