Have you thought about the approach of simply focusing on how much work you can do during training sessions ie how much can you deadlift, how quickly can you finish a WOD, etc etc
If you really focus on that everything else becomes a bi-product of that focus. You will lose weight, you'll look at junk food and think "this will make me slower/weaker, I'm not interested." but you've genuinely got to want to make those increases in your workloads.
This is just one approach but personally I've found it really simplifies a lot of different lifestyle choices into pretty clear "yes/no" responses