I'm sorry, but how can being overweight not affect your health? You may not see the repercussions right now, but you cannot deny the lasting toll it takes on your body.
And I'm not saying he has to change anything at all about himself. I'm saying he needs to quit being a cry baby and not let words affect him from strangers. You don't think each and every one of us deal with negativity on a daily basis about our appearance, intelligence, decision making, and everything else? Muscle through it, especially if you put yourself out in the public eye just begging for ridicule. Hell, people body shame fat people, skinny people, make fun of ugly people, and beautiful people. That's just something he needs to understand and that in this day in age there is NEVER a 100% positive reaction.