That sounds great, but he was playing major college football and still couldn't keep the weight off. It is highly likely that his coaches wanted him to play at a lighter weight, but he couldn't keep the weight off.
Now, he realizes that if he can control his weight temporarily, that he can cash in for a big payday. His motivation to get the weight off is greater now than probably any other time in his life. But once he gets drafted, his motivation will be less, and once he signs a contract, even less.
I wish the young man well, but the team that drafts him will be bucking the odds of him keeping it off. You have to evaluate him as a 380 pound player, because he is likely to revert to that form once the draft is over.