How does IF effect your sleep?

Answered on August 19, 2014
Created March 01, 2013 at 11:59 AM

I've been intermittent fasting for about a week (small meal after my morning workout, then a larger meal in the evening). I've noticed I've naturally woken up earlier than usual this week and not felt tired despite getting less than 8 hours of sleep. The only thing that's changed is my eating pattern (eating less, less often).



on July 02, 2013
at 11:00 PM

That's a crock. When I fast or am in ketosis, I get better sleep. I naturally start dozing off at 9 or 10pm. My brain shuts me down and I can't stay awake no matter what I want to do. I sleep less and better. I wake up at 6am or 7am. I don't think this is a form of panic, seeing how I sleep better and better the less carbs I eat.



on June 01, 2013
at 04:05 PM

Your body is going into worry mode about when your next meal is going to be, when you start waking almost as if you've been scared awake you'll know you are starting to get into adrenal issues.


on March 05, 2013
at 11:54 AM

The only change I made was to the amount of food and the frequency of meals.

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8 Answers


on August 27, 2013
at 08:38 AM

Another possibility is the conditioned expectation of insomnia is actually Palaeolithic polyphasic sleep expressing itself now you aren't so exhausted as to need 8 hours in a single block.

I found the first weeks after I drastically improved my sleep quality, I ended up performing classic biphasic sleep (sleep, wake and relax for a few hours, sleep some more). This continued until I simply went to bed later; perhaps since polyphasic sleep is ill-suited in a monophasic culture.


You have triggered another refined level of fat-burning metabolism and the energy in the fat cells are being released with the resultant energy is truncating your sleep cycle.


on July 27, 2013
at 02:48 AM

this is definitely a crock- I've been doing IF (36 hrs water fasting weekly) for ~ 6 months now. I always sleep like a baby the second night. And until I started IF-ing I can say I had sleeping issues ....



on May 18, 2013
at 01:57 AM

Doing IF for the last month or so.... incredible!!

I sleep like a baby at night and wake up between 8-10am each morning...

before on a lower carb approach I would not be able to sleep at night because low carb kept me so wired from all the metabolic characteristic which it delivers I need not go into detail...


on May 01, 2013
at 09:12 AM

The less i eat the less i sleep ;)

I had a light dinner last night, a steak & veggie/butter soup, i only slept about 7 hours but feel fully rested, if i've eaten a lot i can sleep up to 12 hours with a nap thrown in too! Cannabis usualy plays a role there aswell tho if im honest.

When im into a 3+ day fast i only sleep about 5 hours a night

Goes to show how digestion takes a lot of energy



on April 03, 2013
at 03:42 AM

I'm not an expert on the definition, but I wouldn't call 2 meals per day IF although you're welcome to call it whatever you like. :-))

Anyhow, I usually eat 1 meal per day and the time varies--late morning, mid-day or mid- to late afternoon. I try to avoid evening meals as when I ate SAD I had a history of GERD although it's not usually a problem on paleo.

Unless I'm unusually stressed I sleep in one block (unusual for my age of 66) and instead of the 8-9 hours I needed on SAD I wake up ready to go after 6. I assume I'd need more sleep if I happened to get sick, but that hasn't happened since I first went paleo in April 2011. I've had a few relapses back into SAD and I seemed to need more sleep until I went back to paleo.

I've had to discipline myself not to go to bed too early; I don't walk the dogs until dawn so it's pointless to get up earlier. And it's no fun to lie in bed when you're wide awake and full of energy. Such problems I have!



on March 05, 2013
at 09:19 AM

I've recently started IFing as well, and have had that happen to me a couple of times, too. I noticed that it was odd because I would normally NEVER feel good if I only slept for 5 or 6 hours. I don't always have the best sleep, but I normally feel like shit if I don't get my 8-9 hours. Perhaps what David said is right, but there are some other differences I've made that could also account for my increased energy:

I've started eating a lot more, but following my macros as recommended per leangains I've stopped doing as much cardio, and am now doing crossfit and starting strength, with 1 more recovery day/wk

Can you think of any other changes you've made?


on March 05, 2013
at 11:54 AM

The only change I made was to the amount of food and the frequency of meals.


on March 01, 2013
at 10:49 PM

When I started IF, I felt the same way. I think it's just a matter of going to bed satiated and giving your body all the building blocks to heal right before it's most crucial period of healing that does it.


on March 01, 2013
at 10:43 PM

The Paleo Sleep Challenge may be a good way to help you measure and analyze how intermittent fasting impacts your sleep.

The idea is to help you establish recovery goals, particularly as it relates to sleep. The goals will revolve around "sleep efficiency" metrics and aggregate time slept and will be measured using an app (the phone accelerometer enables the detection of movement which allows you to quantify sleep quality).

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