well, looking at google,it appears to have become the latest fad, so most people will abuse it: people are always looking for a way the 'cheat' Nature, to binge and purge or do penance -- to put it bluntly. Nature would advise a plant-based lifestyle,(not "diet" as people think if that), meaning, you would be eating raw-ish and organic if possible fruits and vegetables, and soaked, germinated (very important) nuts and seeds, not the dead, roasted and such.
So, if you are intermittent fasting, then when you break fast, you would just eat what your body wants--from within that range of food. Maybe it'd be mono meals of fruit for a day. Maybe just salad. Maybe juice and salad. Nut milks with fruit, as a smoothie. Salad rolls. . . Blended raw green soups, with some avocado. . . The simplest way is also the wisest. If you are eating another way, eating cooked food and anything processed then you would have to gauge all that and take an honest look at it--in this case, only you would know 'best'. Ultimately, the body will *tell you what to eat, if you are being honest with yourself about what you are doing. (*Note that this is not the same as the very loud sometimes cravings we get for de-natured food, as I'm sure you know. That is a subject for a whole book. Check the Soil and Health Library for Natural Hygiene, etc.) You will likely get more and more sensitive to what your body truly wants and needs, the "cleaner" you get with fasting, and the amount of food you want and need will decrease, the better quality it is. (It is wise to eat food that grows near you, when possible, since it has a vitamin-mineral profile that is exactly suited to the humans that live there. This kind of *miracle* the wiliest Science can't quite copy. :-))
I would caution to beware of any kind of diet plan with ideas such as 'no-fat' or 'no-cal', or high protein--these are all based on strategizing so that people can follow habits that do not serve them well.
After my Water Fasts I progressively have moved closer to raw and living foods. Nothing looks quite so divine to me after a few days on water, or even a day--since I only eat one meal per day, essentially fasting every day-- as a velvety baby spinach leaf. Then there's a vegan Caesar salad; with a dressing of tahini, dijon, lemon and mandarine juice... mmm. :-) Always, always soak your nuts and get them raw. They are a whole different food than the usual SAD. That should give you a few ideas. Herbs (which is all the greens that grow naturally), nuts, seeds, fruit and vegetables, with minimal grains is the ideal way. So, do what you are able to, to get closer to this by degrees --if it appeals to you!!! --but do not make it something to beat yourself up about.