Boyfriend gone for 6-8 hours working out

My boyfriend used to be very overweight. We went to high school together and he was bullied a lot for his weight so he's been working out to lose weight and over the years he's gotten really fit. Me and him have 2 kids together. We both work except he works part time and I work full time and still manage to care for the kids. A couple months ago his friends said that I'm making him "Heavy Hank again". So he's gone almost all day working out at the gym. I have no help with the kids and when he gets home he showers, weights himself and goes to bed. He works out 6-8 hours a DAY and lives in protein shakes. He also never answers his phone at the gym. I'm also getting worried for him because I think he's really over doing it too. He was gone at the gym yesterday nearly 11 hours since he was off and had an apple and some peanut butter crackers and when he came home he was white and while he was weighing himself he threw up. I told him maybe this is a sign he should give it a rest but he went BACK to the gym today. His goal is to lose 50 pounds this month. He's 6'3 and weights 174

@JS there isn't much more to this story

@Daisy if you're insinuating he's cheating. I know that's not happening.

I know he isn't cheating. He's just really stuck on losing weight that in my opinion he doesn't need to lose