12 Hour Intermittent Fasting, Is It Long Enough?

sleeping alarm

While researching different ways to go about my intermittent fasting diet and as a way to make myself more knowledgeable about the subject, I took a look at the possibility of doing a 12 hour intermittent fasting. When I first read the headline, I was excited. I can fast for 12 hours and then eat for 12 hours. How easy of a diet this would be.

Then my skeptical self stepped in and said, “How can this be? This doesn’t seem like it should work at all.” So I decided to really look at this and try to understand why people would even consider doing this and if you can even really call it fasting.

In this article, I will dive into doing a 12-hour fast every day, the benefits of doing so, what to do about sleep time, what’s the point of this, and then give you my final conclusion and open the post for comments. So without much further ado, here we go!

12 Hour Fast Every Day

Every day there are 24 hours for us to spend in whichever way we want and try to fit all we can into. Some people will sleep the day away and others will work most of it and spend time with or caring for family. And then there are those of us that enjoy rest and relaxation, in whichever form you can find it. Maybe that’s TV, computer games, needlepoint, blogging, reading books, etc.

Now, if we consider the idea of fasting for 12 of these hours, it should be quite simple. We can easily fill most of those hours awake with something of importance to our daily lives. I don’t believe that most people will struggle with a 12-hour fast.

half a day

Let’s consider a day in the life of what I would consider a typical adult.

  • Wake up at 7 am
  • Work from 9 am to 6 pm
  • Home by 7pm
  • Asleep again by 11pm
  • Repeat the process 8 hours later

Now, using the example above: 8 hours of sleep and we are already down to 16 hours left in the day (24h-8h=16h) or 4 hours remaining in our fasting. Now, if we eat breakfast or have our first protein shake at 8am (post-shower and waking the kids) and start our 12 hour window of eating, that means that as long as we stop eating before 8pm, we can maintain our fasting schedule. Pretty simple, really. Almost, like you are doing nothing at all! (Read sarcasm here)

12 Hour Fast Benefits

So with that said, are there benefits to be had from doing a 12-hour fast? The short answer, I’ve found, is yes. How, you (and I) ask? Well, it has to do with the body’s ability to switch itself from burning the foods we eat for energy, to using the stored energy in our bodies (fat) for energy instead. This naturally occurs whenever we stop eating for an extended period and generally begins after a fast of 8 hours.

fresh start

By further extending the fast to 12 hours, we help the body to reduce our overall weight by about 5% a year compared to others that don’t fast for 12 hours AND (this is my favorite part) we allow the body to be able to better regulate itself if, by chance, we have a “weekend off” due to holidays or special occasion.

This is my favorite because I, and I’m sure you also, lead a pretty busy and full life. There are many holidays, many special outings required for various reasons, and people who would love to meet and have a bite to eat together. It is not always socially acceptable to say, “Sorry, I can’t eat that because it’s not on my diet or I can’t eat then because it’s outside my feeding time.” Forget even the socially acceptability of it, just having to explain to someone what I’m doing and why is not always something I want to have to do. So, knowing my body will regulate itself back to the proper fast protocols of using stored fat again within a reasonable time frame is comforting.

Sleeping Through The Fast

sleepingAs I stated earlier, the easiest and probably only way to do a 12-hour fast, is to simply sleep through 8 of the hours of your 12-hour fast. If you tried to do it any other way, you would actually be doing a longer fast than 12 hours. So my suggestion would be to block out 2 hours before and 2 hours after sleep, where you don’t eat anything and then sleep for 8 hours.

Obviously, this schedule would need to change a bit if you are not an 8 hour a night sleeper, but you get the idea. You simply want to break up the extra hours so they are balanced half on each side of your sleeping time. I find that this makes the fast more enjoyable, prepares my body for sleep, reduces most, if not all, stimulants that might cause me to stay awake, and allows me to wake in the morning feeling rested and replenished as my body has been actively converting fat to energy and rejuvenating itself while I slept.

What’s The Point?

questioningThe point of doing a 12 hour intermittent fasting session is that it will allow you to start a very doable intermittent fasting plan, get you started toward a slimmer body, and prime the body for more advanced fasting plans. Its benefits are ones that can be felt and seen over time. You will probably not see super gain (or losses in this case) from this plan as it simply doesn’t provide you enough time in a fasted state, in my opinion. However, if you are at the very beginning of your quest to lose a little weight and haven’t yet started any plan, then this could serve as a good starting effort.

Decision Time

Okay, decision time. To follow the plan or not? I believe that everyone should start here if they have never tried a fasting effort before and are not sure how their body will react to forced not eating, or in this case, timed intervals of not allowing any food into the body.

I think this can be an intro to also seeing if you are able to follow a plan of limited eating. Can you eat only during those 12 hours? Do you eat extra because mentally you think you may starve or are you tough enough to overcome those thoughts? Can you focus yourself to eat slightly less during the eating time to give yourself a boost?

choices to make

If you succeed in this plan or if you think you are ready for a bigger challenge, please read my reviews of the 16 hour, 20 hour, and 24 hour intermittent fasting plans soon to come. I will review those plans and give some tips and advice to help you in your journey to be slowly slimmer.

As always, please comment and share. If you ever have a question or need help with something, please let me know and I’ll do my best to assist you.

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Author: Ryan

I am the founder, head writer, and owner of this site and a few others. I have come to the conclusion that fast diets are not for me and that I should focus on making life changes that will lead me to be slowly slimmer. Thus, I started this site to talk about it. I love to be social, so comment and reply to posts. Thanks and enjoy my content!

12 thoughts on “12 Hour Intermittent Fasting, Is It Long Enough?

  1. Is there any fasting you recommend for burning some fat but not losing too much weight in the process? I’ve tried fasted workouts in the morning but is there any other tips you have regarding this?

    1. Great questions. Working out in the morning is really good for losing fat because your body is at the end of its fasted state so it has nothing to use for energy except the stored fat and thus you will see a difference over time in doing this. Other ways you could consider that have shown promise include increasing daily activity overall or extending the fast for a longer period. I have other posts I am working on for longer term fasting so stay tuned. Increasing your activity could be something as simple as getting 10K steps throughout the day or doing micro bursts of exercise throughout the day. Thanks for your comments and I hope this helps.

  2. Thanks for sharing this interesting article.

    Really impressed because I’m trying to lose weight at the moment. I’ve tried dieting but failed to lose weight.

    Hope this plan helps me but just a quick question; Do you recommend to fast for 12 hours every week day except only the weekend?

    1. Losing weight is certainly challenging. We (my wife and I) have struggled to do this as well, but are really enjoying our intermittent fasting plan. For us, intermittent fasting is a lifestyle. I think to be successful, you need to change your mindset to think of it not as a diet, but as a lifestyle. More than likely if you do this everyday you will see results, you will realize that eating as much or as often as we have been told in the past is simply not good advice, and you will still have energy for everything. So to answer your question, I think you should try everyday, but you can still enjoy special events and holidays. You are in charge of you! Be strong, I know you can do it.

  3. Coincidentally, I’ve been wondering if there were any benefits to be obtained with shorter fasting windows than the typical 16 hours. I’m very happy to see you addressed the topic!

    I actually engage in 12-hour fasts on weekends. Now, I’m sure two days has limited incremental health benefits, but still, it’s good to have some data to ponder.

    And I don’t think there’s any question that 12-hours is an excellent gateway fast for people who just want to try out the concept.

    Great topic, thanks!

    1. Thanks for your comment! Yes, I believe in fasting for the health benefits. I am happy to hear that you try fasting on the weekends. Anytime, even if for the weekend, that you allow yourself to go for a long period of time (12+ hours) you will help to reduce fat stores and reset the function of other bodily organs and functions. So good job there.

  4. I love this idea and it seems like the perfect place to start. Our ancestors naturally fasted because food was not always available to them and I think our bodies function best when they take breaks from eating. This has been on my mind lately but I didn’t know how to start. I’m going to try this and I’m bookmarking your site so that I can check back later.

    1. That’s great to hear Theresa. Welcome to have you and thanks for the comment. Yes, please start here and ease into practicing fasting. If you are anything like me, you will start to realize that this plan actually works and there aren’t too many hardships felt due to restricting your food intake. I look forward to hearing how things go.

  5. wow! Intermittent fasting for 12 hours seems like a great way to lose weight. I have never fasted for 12 hours, the longest fast I have ever done is 6-8 hours. I will be trying this thank you!

    1. Hi Pam. Thanks for the comment. I wish you good luck in your fasting plan. The 12 hour plan is a great place to start. It’s really not that restrictive since you sleep a good amount of the time, but it has great benefits. As you become accustomed to the 12 hour, you can always increase the time if you want additional benefits or simply adopt the 12 hour as a way of life. Anyway you decide, I think you will feel the benefits.

  6. Interesting article on the 12 hour intermittent fast. I know that fasting has health benefits as well as weight loss benefits. This is a fast that I know I could do, as I am doing something close to it now without even trying. The longer fasts though might present a challenge for me. I am looking forward to your articles and tips on these longer fasts. Thanks, Tom

    1. Hi Tom and welcome to my blog. Yes, there are benefits to be had at all levels of fasting starting at 8 hours, but 12 is a starting point that I think most people should start at. I myself am trying out a 20 hour fast, which sounds crazy to even say, but now that I have been doing it, I feel great and am seeing results. I have plans to add blogs on different fasting hours in the future, so stay tuned. I wish you success in your efforts.

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