>

Antipsychotic medications can make people insatiable.  Some kids need them.  
But yeah, Prader-Willi syndrome is as real as it is rare.
Never base childs confidence on his/hers looks which they did nothing to earn them, that's not a strong base, base on character. On the other hand, no matter how your child looks, he/she should be comfortable in their looks, certainly don't feel ugly, even if they don't meet "the criteria" which is subjective. >

Pssst... you're going to get old and wrinkly one day. 
Life doesn't care what you want. With your current outlook, you'd better hope that you stay lucky enough to avoid accidents/tragedies that impact your face. Car accidents, tumors, building collapses, a new autoimmune problem, a stray transport tire, a fire, a falling object, etc can all happen to you unexpectedly. You won't magically be safe from them just because you dislike ugly people.
I hope they don't happen to you, but you'd currently be screwed if it does happen, based on your response. Would you lose all of your self-worth, or would you try to find other things to be proud of? Your attitude implies the former, which is not good. I hope that you have other things that you are proud of. If you don't, you should try to find some, even if it's a hobby. No one is good at everything, but everyone is good at something.
ETA: A bad personality/attitude can easily make a "10" into a "2". Life's way too short to deal with people who prefer judging over self-improvement. You can't guarantee that you'll see tomorrow. >

If you are the parent of a 500 lb minor, you deserve to be in prison for child endangerment (unless there’s some medical reason for the extreme obesity). >

There is only one extremely rare disease that makes hunger continuous that would count as an excuse. Other than that, no other disease makes you eat in a caloric surplus.