the whole 'one hamburger doesn't hurt' mentality is very dangerous if you're aiming to be the best because you're desensitising yourself to the most basic, simple principle of 'junk food = bad.' Yeah, one Big Mac isn't gonna kill you but if you become set in the way of 'one a month isn't gonna hurt', then it's only a matter of time before it becomes 'one a fortnight doesn't hurt' and so on. The reason 'cheat' foods are so dangerous is because they have a high energy density - this confuses the brain and rather than filling you up it encourages you to eat even more -I'm sure some of you have experienced this feeling of just being able to eat and eat stupid amounts of junk food in the days following intense training sessions...it's because the appetite system has become confused. It makes it incredibly difficult to settle into a normal, healthy eating routine.