I wonder if you will be 'lunch' when you are finished the fast?
Relating to a natural diet, when we got our Maine Coon kittens 2 1/2 years ago, I kept them on their breeder's commercial diet; then, once I got them to a homeopathic vet, I changed their diets to raw food (they have weak immune systems with all of the breeding) and they never had fleas. We had to go away overnight once and so I got a good commercial product to tide them over; then, when I next offered them their raw food, they looked at me as though I were nuts! Where was their 'chocolate cake' (i.e. commercial food). In just one day, they were addicted! I could never get them back to the raw food and decided to let it go. This Last Fall, I noticed that the weaker of the two had fleas!
The treatment for that is a powerful systemic drug -- good for a weak cat? No, and I know that I have to attend to it before Spring.
With their natural food, they were able to resist fleas (they are never outside).
That's why I am wondering if you will be less appetizing once you are finished the fast -- for whatever reason they are attracted to you.