What did you have for dinner tonight?
I had a small hamburger from McDonald's about 1400, no fries, and nothing since.
Since you're likely to keep eating McDonald's, here are some recommendations:
1) Drink water or at the very least, diet soda (I know it has some health concerns, but getting weight down is far more important and if he can't stand water, it will have to do)
2) DON'T EAT THE BUN. That's a ton of empty, needless calories. Ideally, make it a Jimmy John's-like "Unburger" wrapped in lettuce, if possible (or just eat it with knife/fork and order salad on the side)
3) If you're hungry at home, just eat peanuts, microwaved vegetables, fresh fruit, and dark chocolate. These are far better snack choices than what you're having right now.