I'm going to stick my neck out here, and take a guess.
It all depends on what the Fast was for. If one is Fasting to lose weight, or to heal a physical condition, then the post-fast Diet won't change much....it may even become worse because the one losing a lot of weight now has 'wiggle room'.
If one is Fasting to change a poor Diet, or to heal a food addiction, then the Diet change has a better chance.....WY