I suggest reading Eat Stop Eat by Brad Pilon, he goes over the science of fasting for fat-reduction quite thoroughly. Personally I find it to be VERY effective. I don't count calories or carbs, but I eat in three hour windows and fast 24 hours (so basically I'll eat from 9am-12pm, the next day 12-3pm, the next 3-6pm, then a full 39 hour fast, then reset back to 9am-12pm). So I do a very extreme version of it, which is closer to the Warrior Diet idea. The energy is amazing, first of all, and the fat-loss is more than I've ever experienced in such a short period of time. I'm also making sure I have adequate nutrition in those 3 hours. For me, it's a lot easier than being low-carb constantly - I would rather eat all the fruit and veg I wanted if I felt like it without worrying about gaining weight back or plateauing. Much easier time being paleo when I fast too, because when I fast I find that I become "disinterested" in food. I noticed that yesterday actually, I was hanging out with a bunch of people gorging on pizza and cheesecake, and walked by several bakeries and Italian restaurants. Normally that would be my own brand of torture, but it just... Doesn't bother me anymore. I'm immune :P

It's not really proven that there are any benefits, especially if you're not trying to lose weight. There is some evidence that the stress it causes our cells is beneficial and that it causes them to start recycling junk proteins, but a lot of that is still very speculative. Obviously to the extent that it causes you to lose weight if you are overweight there will be benefits, but those are because you lost the weight, not because you fasted specifically.

Have you checked out leangains.com? Lots of info there.

The only thing is it is a TON of information. I haven't personally waded through it all so if anyone has and could post a synopsis I am interested too

I just completed my second 24-hour water/tea fast, and I thought I'd share my experience so far. Disclosure: I've been lacto-paleo for over two years, and have become extremely frustrated with my lack of weight loss during that time. I'm not severely overweight - I'm 5' 9" and about 145 lbs/size 8-10, but I'm most certainly what you'd call "over-fat." Don't get me wrong - I feel fantastic on a paleo-style diet and know too much to ever go back to CW - but I would be lying if I didn't admit that I've been disappointed that (aside from the initial water weight loss) I can't seem to budge these stubborn fat stores.

Enter fasting. I rarely eat breakfast during the work week, and generally only eat two meals a day anyway, so I've kinda been practicing IF all along. On a whim, I decided to take it to the next level - to try skipping dinner one night, and not eat again until lunch the following day. I was pleasantly surprised at how pain-free my dinnerless evening was, and that night, I slept like a rock. The next morning, I felt light, but not not hungry at all. I had a few cups of tea throughout the morning, and by 2 p.m. (when my fast was scheduled to end) I still didn't feel any strong urges to eat. So I held out until dinner, roughly 4 and a half hours later. No sweat! More than anything, I was shocked by the level of energy I seemed to have during the fast. I never felt weak or tired or dizzy (things I was kinda expecting) - on the contrary, I felt like I could have leapt tall buildings in a single bound. I had doubted whether I would be able to exercise (Slow Burn-style free weights) while fasting, but I think I would have been hard pressed NOT to exercise. Just crazy amounts of energy.

Bonus: This morning, I noticed that my jeans are significantly looser. SOLD!

I intend to do one to two 24-hour fasts a week from now on. It's ridiculously easy, and I love the way they make me feel. For anyone who's curious about fasting, I highly recommend you try it. I like the idea of working up to a 24-hour fast in stages - I imagine that if I'd been accustomed to eating a big breakfast every morning, 24 hours cold turkey may have been a different experience.

It's been my understanding that fasting (at least, intermittent fasting) causes your body to use fat stores as energy rather than using food as energy, but not at great length. I've done it and have had positive results, with the exception that I usually do IF at night, and drink iced black coffee or water during the fast. I also know when I start feeling serious hunger pains that it's probably the right time to eat something light and not cram food in my face to make up for what I haven't eaten.

You will lose a little weight, perhaps, but I would DEFINITELY NOT rely on fasting as a way to drop pounds. Nothing good will come of that.

To me, the best part about fasting is reducing the amount of time you spend eating and preparing food, while at the same time taking control of your hunger.

The key seems to be loading up on nutrient and fat dense foods during your eating window. One of my favorite 'recipies' is:

1. A pound of ground buffalo with some assortment of vegetables and spices, along with an avocado and lots of sour cream.
2. 500g fage total + berries to taste
3. Heavy whipping cream (maybe with some ice cream, maybe i just drink it)

Also, learning to fast is a gradual process. If you are excessively hungry, break the fast with an egg and two or three slices of bacon.

I've posted some links to pro-IF studies here in this thread.

Fasting has been shown to increase insulin sensitivity or at least the sensitivity was higher right after the fast. And this was in people eating the whatever normal maybe SAD type diet. But fasting might be something to explore with a bit especially for those with poor resting blood sugars.

Personally, I would suggest people first adapt fully to paleo, which may take up to 3 months to really settle in. Once you are fully comfortable and have sorted out any probs with paleo eating, adapting to less sugar, etc. And are sleeping well and feeling good all day. Then is the time to think about fasting, and do it gradually. You should not be making yourself feel miserable with fasting. It's not supposed to be about suffering.

THere are times and days when I just don't feel that hungry anyway, and those I find are good days for me to skip a meal or two. So I don't really plan it personally. I just go with what the body says. If it's meal time and you are not hungry, why not skip it! But first make you are healthy and balanced. Skipping meals can be a big stress on the body if not done right and not done when you are ready for it. I think many things about paleo are highly safe, but I think fasting is something that should be approached very carefully for any people that are not totally healthy.
-Eva

I have been practiving IF for a few month now in the form of a feeding window. I eat between noon and 8pm daily thus, giving me a 16 hrs fast. I personally have noticed a lot of positives. Weight loss, increased energy, ease of schedule, more free time, mental clarity, increased focus, food tastes so much better when I do eat (almost a euphoric feeling). Also, I absolutely prefer working out and playing soccer (couple times a week) in the fasted state.

This way has worked for me. If you wanted to try it, I would just skip a meal and see how you do. If it works, and you like it, you can always add time to the fast. Just make sure that when you do eat, you eat enough calories. I have noticed that I rarely get hungry anymore, so I have to remind myself to fuel up.

Good Luck :)