I've seriously cheated for two short periods since I started Paleo about a year ago. The first time I didn't notice anything too terrible. The second time, I gained about 10 pounds in 10 days (and felt terrible during that time), and have been unable to reverse the gain in the two months since then. It feels like the longer I'm on Paleo, the more sensitive my system becomes to cheats. I can see it with blood glucose measurements, too.

In other words, to answer your question, no, I don't think a fast will compensate for a cheat. You might deplete glycogen stores, but a carb spike will disrupt insulin levels in a way that can last for much longer. I can't think of a good after-the-fact food-oriented compensation for a sudden insulin spike. One approach might be to take a supplement like resveratrol, alpha lipoic acid or carnitine, which can temporarily improve insulin sensitivity. That might help minimize the metabolic mayhem that could otherwise develop. Doing a very vigorous workout might also help, since that can also increase insulin sensitivity.

As someone who has struggled with eating disorders for 30 years, sugar is poison to me, I would hazard against this king of behavior. It starts innocently enough, but for a surprising number of folks this kind of stuff leads to some severe behavior to manipulate weight. I've yet to meet someone with food issues who stated it began intentionally, usually it begins with some little behavioral changes and next thing you know it's out of hand. That being said, I do regular IF, but base it on a schedule of time, not eating behavior. Trust me, eating disorders SUCK so be careful with such "balancing" efforts.

I like it and do it. I mean, there are a lot of caveats: I think that not "cheating and fasting" is better than "cheating and fasting", and that one should be careful of potentially dangerous binge/purge habits, and watch out for doing this too often, because the fast doesn't actually make up for the cheat (only partially) in a health sense. But with all these caveats, I think fasting before or after a cheat is a good way to partially balance it, as well as having more flexibility and spontaneity in your life.

One reason I do IF instead of paleo is that flexibility.

I agree that exercise will help burn off the extra carbs. But I think we’ve all done this. I pigged out on sushi recently (fish good; panko, sushi rice and mayo sauces, not so much). I skipped the meal before, and I was so stuffed afterward that I didn’t eat again for a full day. It just naturally worked out that way. It feels right to give your body a break after you’ve abused it a bit.

Most of us have probably fasted in anticipation of a special meal as well. I’m not going to turn down my Sicilian grandmother’s stuffed artichokes. So I’ll skip a few meals beforehand and enjoy it guilt-free. I think this gets down to the understanding that intermittent fasting has benefits even when one does not strictly follow a paleo diet. Eades has written about this, and I think followers of the warrior diet would concur. I personally can’t make a habit of it without completely going off the rails, but occasional feasts accompanied by fasting is not unnatural to man. Unless your metabolism is broken (or your cheat meal becomes a cheat week), I wouldn’t sweat it.

(Regarding cheats, Kurt Harris had a great rant recently on resisting social pressure to eat poisonous foods; I admire the zeal, but I confess I’m not all the way there yet).

I usually don't do a full fast after a cheat day, I'm more likely to do a zero carb day instead which seems to re-set my body, or a vegetables-only day if I'm at that rare point where eating good fatty foods is going to make me feel ill. And that's only if I feel very terrible, because the fast makes me feel better. If I'm hungry, I don't fast, I eat better food.

Otherwise, my fasting days tend to be planned ahead of time. Fasting just because you cheated can easily turn into an eating disorder. Habitually fasting after a binge is a form of bulimia and I'd advise people not to get into the habit.

My hardest thing with intermittent fasting is that my type 2 diabetic partner eats three meals a day and likes company. It is hard to sit beside him and not join in unless I am sick (which I am not very often).

Sometimes I'll wake up and not care about breakfast but in the course of feeding him I get sort of sucked in. On a down day, when I didn't eat anything but a cup of homemade chicken broth in the evening, I felt great afterwards.

I guess I just need to do what I need to do, when I need to do it, and not feel the need to explain or join in.

I don't really "cheat" since I've come to associate those foods with poison, but I would think that a higher level of activity subsequent to the event would dampen down the blood glucose spike and thus prevent the insulin response.

Using fasting afterward sounds a lot like an eating disorder.

I like to fast BEFORE a cheat or before a feast. My normal fast is 14 hours minimum, but on days like Christmas, or when i know I am going somewhere to be social, I fast ahead of time. I try to make sure to get a good fasted workout in that day as well. If I have enough preparation, I try to go as low carb as possible for a few days ahead of cheat day, so the insulin sensitivity is high enough to cope with the rush of crappety crap food.