Boyfriend letting himself go?

Me and him have been together for over 4 years. He’s 20 I’m 19. Over the past year he’s been gaining a lot of weight, eating unhealthy and lying about it, etc. When we went out for the first time after a month of being apart, I dressed up for him. (I think it’s important to still impress the one your with, look sexy etc to keep spark alive) ....he hadn’t had a haircut, his lips were chapped and didn’t dress in anything special for a date. I do love him, but at our age we should be at our healthiest and be the best we can be in all areas. I myself, workout 3-5 times a week and try to eat as healthy as possible. It’s just frustrating... he used to be so fit and into the same lifestyle as me and now he’s just sluggish and low energy all the time...what do I do? I’m losing physical attraction..