If its sleep apnoea, which it sounds like, he's never getting into REM sleep, because his breathing is stopping and his body is waking him up all night. You'll find he won't be able to lose weight on his own, because his body simply won't provide the energy required - he's basically not getting any sleep! He needs to be referred to a sleep clinic, where they will monitor him overnight to see how many times he stops breathing. I don't know the exact numbers, but if its considered serious, he'll be given a CPAP machine, which will force oxygen into his nose/mouth through the night, and give him a proper nights sleep. You'll be amazed at the difference once he starts getting a decent sleep, and he'll start losing weight as well, which will eventually mean he won't need the machine