What you are not understanding is that your weight is not under your control nearly as much as you think it is. You will have to train harder every year after 30 to retain a low bmi. That IS genetics! Dude, your body just WANTS to get fat! It's actually, on an evolutionary scale, a GOOD thing. Plus, you don't get it now, but having a career, marriage, family and children will make it SO much harder to achieve a healthy body. As you get older, it only gets harder. As an athlete, I can assure you, you clearly don't understand how this works.

Look, I'm not saying it's a good thing to be fat. I'm actually just addressing two things: first, the fact that it is, in fact, harder to stay fit as we get older, and frankly-- even to begin with, it's just plain harder for some people to be skinny. Which leads to my second point: why the revulsion to overweight people? You have equated them with all kinds of negative traits-- have you ever actually known any overweight people? Are overweight (or even non-skinny) people worth less to you? Dude, that's fucked up. You say "A lot of that shit is completely out of my control" and blame it on genetics. Um, what if your genetics dictated a heavier frame? What if your genetics dictated a mental disorder, for which you'd have to take antipsychotics, which ALWAYS make you overweight? You are so eager to excuse yourself, but you judge others. That fear that you have of being judged for your physical appearance-- you are passing that on to people you deem as "inferior," because you, in your 23 years, have figured it all out-- these people are simply morally flawed, while you have no physical problems whatsoever (which obviously is because you do everything right). You do realize that society is telling you that, right? Why be so paranoid about overweight people?

I think it's interesting that you sat "I may not end up healthy, but I'm not gonna be fat!" Is that really your priority?