There is absolutely no doubt that extreme diets-and this includes contest diets, can lead to eating disorders and disordered eating: food issues/weight issues/diet issues etc… And this is not opinion this is well researched fact. Anyone who tries to present a counter-position to this is either ignorant of the research or just plain irresponsible. Does it happen to everyone? No. Can it happen to everyone? Absolutely. And the point to make here is if you suffer from some sort of post-diet eating or food issue, the fault is not your own.
All kinds of medical literature exists about the "natural protective mechanism" of BMR downgrade from dieting. However, medical literature also indicates that when prolonged or frequent dieting occurs, such BMR adjustment may be permanent! Therefore, repeated bouts of dieting and training to compete can permanently alter metabolism for the worst. If you have a coach/trainer pushing you to always compete, to "get your face out there," you may need to reconsider both the advice, and the advisor!
Unfortunately, physique competition also seems to appeal to some people who are least genetically suited to do it, thereby again increasing the odds of metabolic damage. It is a fact, although no one wants to admit it, that many active individuals just do not function well at very low levels of body fat. Many also cannot healthily achieve it, nor should they try. This is a reality no one seems to want to recognize. .
Do not fall prey to cultural or coaching pressures in setting unrealistic body composition goals. A experienced coach will see the bio-feedback signs and know when to stop. Make sure guidance is based on what is best for you, and what is reasonable for you as well. If not, the road may lead to shortcuts that have long term adverse consequences.
If you are following crazy pre-contest rituals of ultra-low caloric intake and marathon cardio sessions, Both are unnecessary and ill-advised.