I do 18hrs every day. Its natural to me now so I dont even think about it.

I fast everyday 8PM - 6PM with four cups of bulletproof coffee (two tbsp clarified butter + two tbsp MCT oil) in the mornings around 9AM and 10g BCAA's before my workout at 4:30PM.

I am new to it and I do an easier 14/10 or at least a 7pm to 7am. That's my opinion. Primal/Paleo allows me to go further, but I am still pretty reliant on food to feel able to do my work(desk job).

I can only do so much. Usually somewhere around 7-8PM to noon the next day. I could go longer, but I get fuzzy and it's tough to concentrate. If I was a bit more practiced, maybe that would go away.

I think that the various methods of fasting fits better to certain people. For instance:

• Eat stop eat (24 hour fasts 1-2 times a week) would fit someone trying to loose weight.
• Leangains style for maintaining non-fat bodyweight, especially if youre prone to overeating.
• "Primal fasting" for peolpe that likes the freedom of doing whatever their body tells them.
• Warrior Diet - just a cool name.

I used Leangains approach to fasting before I went primal, it worked very well. The problem is adherence - counting calories, non-fat days, non-carb days, 300 g of protein and so on - for strictly following the protocol. Since I went paleo (recently) I decided to do the fasting as it comes naturally. But once or twice every month do a 24 h fasting to reevalute my relationship with hunger. What is real hunger, and what is only my phsycological eating habits?

I fasted for 720 hours (30 days). There are no shoulds with paleo. The original paleo folks did not have a set time that they would go without eating. Sometimes food was plentiful; sometimes it was scarce.

I fasted with raw veggie juice (that I juiced), one or two eggs blended into the veggie juice, and 2 tablespoons of coconut oil in the morning, and one and only one cup of homemade kefir for lunch. I could drink as much veggie juice as I felt like. This ensured that I got enough micro-nutrients. I do not recommend any fruit juice during this fast. It will make you hungry and contributes too many calories.

I dropped 25 pounds doing that.

I modified what I learned from this site and his movie: http://www.fatsickandnearlydead.com/

Joe Cross is nearly paleo, except for his misguided veganism.

I tend to eat a LOT so I typically follow a 16/8 6 days a week, and then I try to do another 20-24 hour fast at least once a week. Experiment and see what works for you.

Fast until your hungry. Why would u force ur body to continue doing something it doesn't want?

I am now 290 lbs. but am a natural faster. It just feels right to me. I'm just not that hungry in the morning 'till I eat. Then I'm hungry for the rest of the day. If I wait 'till 4 pm to eat, it's not that hard for me. So what I do is eat from 4PM to 7PM. Usually a couple of meals, but always less than 1500 cals.Then I do it over and over again. I do not eat any junk food. I've tried all the so called "sensible" diets. They just don't work for me. And the more I get used to this method, the easier it is to do.

I usually intermittent fast for 16 hours three days a week, though I could easily do it every day since I am fat adapted. I try to do a 24 hour fast at least twice a month to help lower my chances of getting cancer.

like many, if not most, things 'round these parts, it depends.

i do leangains style (16/8) fasting when training hard.

i do eat-stop-eat style (24 hour fast once or twice a week, two to three meals other days) fasting when i take a month off from training or on the weeks that i travel for work.

tinker with it, based on goals and activity levels.

ps - i don't count calories and the like, i do stick to paleo and just add a bit more starch in the form of white rice / sweet potato in the post-workout meal (and eat a bit less fat that day) when on leangains style approach.

naturally, i fast for about 12-14 hours a day. i don't think i could go any longer without fainting since i'm anemic.