Leave when she eats so it doesn’t tempt you. When she sees you get sexy, maybe she’ll want some too. That’s your best bet. You can lead a horse to water but you can’t make it drink. All you can do is bring the horse back to water over and over again.
Some people have called this the 1,000 foot tow rope. You’ll have to go that way for a long time before all the slack is out. You’ll have to prove its not a short term fad, but a new long term reality. Keep pushing to be the best you can be. Don’t whine to her about the food, but make yourself scarce when it’s not helpful.