In addition to more calories, I think you need more protein. If you are exercising 5 days a week, you may not be getting enough protein to maintain and repair muscle. Or if you never exercised before, you could be building muscle but still losing fat but it won't show on the scale. There are so many variables. Have you lost any inches?

IMHO the fat fast and induction will not help you eat more. It's not a matter of 'how much' you are eating, but maybe 'what' you are eating. Choose higher calorie foods, like beef and pork instead of chicken. You probably are not getting enough fat either, eating tuna and chicken. Cream cheese is also good for adding calories and fat. I like it on celery. How about a few berries with heavy cream? That's my favorite treat.