i learned from the u of minnesota that yeah that is badd for you but have him lose the weight at night go to the gym the bike is the best to lose the weight free running will burn him out so id say check his weight twice once after the work out give him a drink of ice water to get his metabolism going if hes close then send him to bed if hes over like that he wont be able to eat that night anyway check his weight in the morning if hes close then have him shake his leg in class at school or wherever he his and whatever he has the option to do but he can always just not eat till weigh ins i know its bad but thats the best i can do i normally am down to my weight 2 days prior so i have breathing room to get something to eat fluids are worse so keep him away from to much jsut enough to stay hydrated is enough thats what i got for you