T Nation

Fasting 20/4


Has anyone tried the 20/4 fasting method here? If so, how did it work for you? Did you experience any noticeable fat loss or strength loss during training?

I am very curious about it and I am debating on trying it out and want to get the thoughts and experiences from people who may have tried it.



I'm doing somewhere between 16/8 and 20/4 depending on how I feel on the day. I've been doing it for a year now.

I feel much sharper and more energetic doing it, and I'm gaining strength at the same rate I was before.

For the most part I've eaten maintenance calories, and it didn't really have any impact on my body composition. I tried cutting on it and it went very well and I maintained my muscle mass and strength, but I've never cut before so I have nothing to compare it to.

Hope this helps.


Do you schedule your workouts right before your eating time?


Start off with a 16/8 and slowly tighten it up over a couple of months till you get to 20/4

Pre- workout - I break my fast with 20grm protein and 50 grms waxy maize about 10 minutes prior to lifting.

Right now I am at 17/7 and doing nothing to change my diet from before I went from 238-220 in 4 months. I am now starting to clean up the diet for the next 6 weeks before trying a fullblown "weigh-your-food-count-your-macros" eating plan.

Kept all same strength as well.

Edit: I train at 11am so first meal is 11 am last is before 6pm


When I was cutting I broke my fast with a small meal 20 min or so before my workout. Usually I had 20g biltong (like beef jerky), 25g cashews and 25g almonds. So barely any carbs. Then I had my main meal straight after the workout. Then one or two hours later I'd have some eggs and fruit.


I do anywhere from 14/10 to 18/6 depending in the day hunger, activity, energy, and if free food is being offered


Also, I do find that when I do 20/4 the hunger gets to me a bit more and I can get irritable in the last hour of the fast. I think that 18/6 is my sweet spot, I think you just have to experiment and see what works best for you.


I'm probably closer to a 21/3 tbh. Incredible for fat loss in a reasonable deficit. I've been fasting in some form for a little over 3 years now, so my eating pattern has just naturally progressed to this. IMO, 16/8 probably your best best if your goals or more focused toward muscle/strength gain. But I've been able to maintain strength/muscle on 21/3 just fine.


I have never heard of this technique but it sounds interesting. My only concern is that I can rarely sleep with an empty stomach. One of the diet coaches on T-Nation, Nate Miyaki, recommends cutting calories throughout the day and feasting right before bed to ensure good sleep.

I suppose you could put the 6 or 4 hour window to where it would end right before bed, but that would interfere with a day job and working out (assuming it's early in the day).

Have any of you guys had sleep issues on this regimen?


I'm pretty sure most have their eating window at the end of the day. Very easy to skip breakfast and have a late lunch


I have done a 5pm-8pm eating window without tracking calories for several months; it was a horrible experience. Not eating was the easy part, I was never hungry until I started eating. Once I started I had an insatiable appetite, I would eat ("clean," paleo friendly foods) to the point of physical discomfort. It might not have been so bad if it wasn't for the high fiber content. I lost my ability to feel full. My sleep was very disturbed during this time. I did not notice any fat loss going by scale weight or before/after pics, but I was already pretty lean undoubtedly with a much lower metabolism. Others have also reported losing the ability to feel full from eating. If you want my advice, I'd recommend at least two very seperate meals and an eating period NO SHORTER THAN 4 HOURS.

Obviously many people report success, so take this anecdote for what it is. Ultimately timing plays a very small role, and whatever is easiest is going to set you up for the most success.


Thanks everyone for your replies.

This is one of the things that intrigued me about fasting in the first place. I feel very lethargic when I eat several meals spread throughout the day and I recently had a desk job fall in to my lap which makes this only worse. I read that people have experienced gains in attentiveness and feeling less tired throughout the day. I've played around with reducing carbs and have tried different carb sources as well but nothing really works. I figured if I eat everything before bed it won't matter.

I'm sorry it didn't work out for you Dave101 and I think I will take you up on your advice about separating the meals.

I'm starting this tonight and I'm planning on something around a 18/6 or 19/5. I want to break my fast before my workout with Gatorade and BCAA's. I plan on running 2500 calories which should be around my maintenance. I plan on running a diet high in protein and fats and sweet potatoes will probably be my main source or carbs I seem to tolerate them and oats the best. I will check in periodically and share my experience.


I have. I like it a LOT for fat loss. I like it far, far less for not losing fat. (I won't use the 'B' word to keep it simple.)


I've been following 14/10 most days for about a month or so now and fat just keeps slowly dripping away. I haven't really buckled down either, I just try and eat carbs right before, during, and after my workout. Dropped from 210 to 196 and I think mos tof it is from this little change. Strength hasn't really suffered either.


I'm basically doing this as a cut (after a 20 year dirty bulk.)

Main benefit for me is compliance. It's easy as heck. I should mention I'm also running ECA so I basically never feel hungry. Your mileage may vary.

It's hard to overshoot calories on one meal a day, in short.



This is just as a quick aside, I don't want to hijack the thread OP but, I feel it's related. Have any of you guys (or girls) tried a once a week 24 hr fast like Berardi recommends? Results?


Terrific success.

Many cheeseburgers and terrible foods were eaten afterwards with only good results. (Not kidding.)


I cant make it a full day without eating :frowning:

I also have had success with IF gaining or cutting


How the holy hell do any of u if guys get ~3,000 cals and 250 grams of protein in those tiny windows? I struggle fitting that into my 7/17 all day feasting..


I get 5-6k in a 6hr window. Low fat high carb med pro. Depends on the person. If you cant get your cals in fasting is not for you. No biggie