Better Health via Intermittent Fasting and a Low-Carb Diet

I’ve been on a low-carb diet now for about two-and-a-half months. This has consisted of eliminating all breads, potatoes, and starchy foods from my diet (Regarding fruit, I pass on bananas with only the occasional apple while still eating berries and other colorful fruits). Furthermore, it has involved intermittent fasting. Through this diet and with minimal exercise, I have reduced my body fat percentage from around 20% to around 10% representing a loss of some 15+ lbs of fat and the gain of a handful of pounds of lean tissue (Weight change from approx. 182 to 168).

This weight loss was the easiest, most satisfying change in my health and body composition I’ve ever experienced.

As this post is extensive, here is the general breakdown:

  • Intro and Intermittent Fasting
  • Low-carb diet
  • Implementation and Conclusion
  • Additional Reading
  • Footnotes

Here are the details:

Intermittent Fasting

Yes, you read correctly, I used the “f word”: fasting. And I can read your mind:

  • What? You starved yourself?
  • Is that for religious reasons?
  • Yeah, that’s called anorexia!

No, no and no. And if I missed any others, no to them, too.

I first got turned onto Intermittent Fasting (IF) via Richard Nikoley over at Free the Animal who had been practicing Art Devaney’s evofitness sans fasting for about a year. Upon trying IF, Richard immediately noticed results in the form of both significant weight loss as well as change in appetite.

Richard’s successes seemed interesting enough from a distance (Fasting? Fascinating but not for me!), but what catalyzed a personal trial in IF and low-carb came after watching a lecture1 by science writer Gary Taubes, author of Good Calories, Bad Calories (“GCBC”).

The big takeaway from the referenced lecture was that insulin, not overeating or under-exercising, is the chief culprit in why people become fat. Since eating carbohydrates causes the pancreas to secrete insulin, there is a direct correlation between carbohydrate consumption and insulin secretion. Ipso facto, the argument is made that eating carbs makes you fatGCBC.

Could it really be that simple? Dieting and working out had failed to reduce my weight effectively — it certainly seemed like something else was affecting my weight. Richard’s success and Taubes’ conclusion sufficiently piqued my interest. Admittedly without knowing all the data, I chose to do an IF, low-carb experiement.

What exactly is intermittent fasting? Intermittent fasting is choosing not to eat for a set period of time, which unlike your daily sleeping fast, is a sustained break from regularly occurring feeding. Translated into some bright line rules, I’d define an intermittent fast as going at least sixteen hours without eating (call that a “short” fast) or going for as long as 30 – 36 hours or three meals (“long fast”). As defined here, a fast requires there be no dietary caloric load on your body.

Fasting for longer than 36 hours likely will not only result in diminishing marginal returns, but it could also start messing with your metabolism. Most obviously, all fasts must be broken by eating.

Completing one to two long fasts per week so long as they are separated by eating a few meals can result in some drastic health benefits while causing no harmful effects on metabolism so long as you are completing some form of regular high-intensity exercise2.

What happens when you fast? Some interesting biological things, apparently. For one, the body moves to mobilize fat stores from the adipose tissue (the fat under your skin) to consume the fat as energy. It accomplishes this fat mobilization as a natural extension of reducing insulin concentrations in the blood as well as an increase in fat mobilizing hormones such as adrenaline, noradrenaline and growth hormone. Interestingly enough, growth hormone is also released to conserve protein from catabolism. Protecting the proteins in your body during a fast is important because your body needs its lean tissues to survive (be they muscle or organ).

A benefit of fasting (for your mind) is that it alters your perspective on eating. At the end of a 30 hour fast, you want to eat something good for your body. You don’t want to gnosh on some french fries, slam a sugary soft drink and eat a bowl of ice cream. Even more, via abstaining from food even when it is available for consumption, you are putting your mind in control of your behavior. Taking back a bit of control over your life is an empowering feeling that leads to improved self-image and confidence.

Biologically, whether fasted or fed, your body is going to take measures to maintain adequate energy flows to demanding muscles and organs. Your body gets this energy from dietary sources or from storage within the body. The key here is that your body is always working to strike an appropriate balance (homeostasis) given the current demands. Were it not managing this process, both eating too much or eating too little would result in your untimely demise!

The ability of our bodies to regulate energy during times of feast or famine is evolutionary engineering. It is reasonable to posit that homo sapiens have only recently lived in such abundance that they could expect to eat food throughout the day, three times a day or more. Go back 50,000 years and you’ve still got mostly the same genetic footprint for human beings, but an entirely different supply of food. These were times when “foraging for food” meant more than a run to the pantry. In other words, our genetics have been engineered to allow us to go without food for longer than ten hours without resulting in our bodies failing. For a tidbit more on the evolutionary aspects of intermittent fasting, see footnote 7.

The bottom line: by reducing insulin in the body and up-regulating fat mobilizing and protein-protecting hormones, IF naturally turns your body into a fat burning machine. During a fast, your body will use whatever energy necessary, which will be similar to the amount of energy required were you eating normally. Over a long fast, if your body requires 2,500 calories, you could expect the majority of that energy to come from fat stores. Thus, the combination of IF with exericse is an effective way to reduce fat stores and work towards a leaner body composition.

Now, the astute reader asks, “Couldn’t you switch your body to being a fat burning machine by cutting out carbohydrates from your diet? If you only ate fat and protein, your body would have to burn the fat for energy, right?”

Good question!

Low-carbohydrate diet

And the answer is, of course, yes! The metabolic pathways while on a fast are the same processes when on a low-carbohydrate dietGCBC (Also see Eades here). This is because in both states (fat/protein-fed or fasted) your body is going to rely on free fatty acids as its main source of energy. Does it really matter that the fat comes from dietary sources or from your cells? Apparently, not3.

If you want to know a ton more about this, and I reiterate this in the footnotes, pick up Gary Taubes’ Good Calories, Bad Calories, an exhaustive book about the science and history of the low-fat-is-healthy hypothesis, the varying research studies behind low-fat diets, the research behind low-carbohydrate diets, obesity, diabetes, insulin, caloric restriction, exercising to lose weight, metabolic syndrome, some biochemistry and more. GCBC is a fascinating and eye-opening read.

As noted before, Taubes concludes that insulin is uniquely fattening. And again, since insulin is released after eating carbohydrates, carbohydrates are fattening.

Insulin is a hormone produced by your pancreas that regulates blood sugar, or glucose. Glucose comes from carbohydrates either directly or upon digestion. The presence of insulin downregulates fat mobilizing hormones (Human growth hormone, adrenaline, noradrenaline, glucagon, for example). Upon the introduction of insulin into the bloodstream, free fatty acids are driven back into fat cells for storage as they are now deemed unnecessary given the newfound energy. When all this energy leaves your bloodstream, you get hungry! In this manner, consuming carbohydrates not only shuts down fat mobilization but it can even spur hunger.

Furthermore, insulin tells your liver to take glucose and make triglycerides or fat for storage. Even more, if you note the “glyc” in triglycerides — that is for glycerol phosphate which holds the long fat chains together. Guess where your body gets glycerol phosphate? From metabolizing glucose! Thus, not only does the presence of insulin spur hunger and fat manufacturing by the liver, but the glucose facilitates fat creation by providing the molecule necessary to build the fat!

Insulin, by way of carbohydrates, is like the triple threat to being lean. It follows logically that by reducing insulin concentrations in the body, you can curb hunger, stop fat storage, and maintain the fast-induced fat mobilization process discussed earlier.

You reduce insulin concentration by fasting and avoiding carbohydrate-dense foods.

Though it is unnecessary to fast while on a low-carb / carbohydrate restricted diet, fasting speeds things along via caloric restriction overall while still allowing you to eat normal meals when you do eat. Taubes contends that a fast effectively accomplishes the same thing as Atkins’ induction phase, which is a two-week period of eating twenty grams of net carbohydrates a day or less4.


Though this is by no means the way to implement this diet, this is my semi-specific methodology. You must pay attention to your own results and customize a system that works for you.

Fasting: On a day when I plan to start a fast, I eat breakfast and lunch. Then I eat nothing else until dinner the next day. During the fast, I am free to drink water, tea and coffee so long as no creams or sugars are added. Some even say diet soft-drinks are ok but I universally avoid artificial sweeteners. All said, this results in anywhere from a 26 – 30 hour fast.

I make it a point to do about twenty to thirty minutes of high-intensity exercise about an hour or two prior to breaking my fast (typically some combination of multi-joint weight-lifting like dips, pull-ups, squats, kettlebell exercises, etc.). Whether you do your high-intensity exercise while in a fasted state or not, the exercise must be done! It is not optional.

I break the fast with a nutritious meal with normal-sized portions. In all meals, I avoid or eliminate carb-heavy foods. I avoid bananas and apples and all juices while regularly eating all types of berries, tomatoes and avocados. Nuts are okay though peanuts are not nuts but legumes (I still eat them from time to time though).

As far as portion size, Art DeVany says, and I think this is sound advice, to eat to satisfaction not to fullness.

Breads, potatoes, legumes and candy are off limits. Yes I cheat from time to time. I accept it and don’t allow it to overthrow my broad efforts. I find myself cheating less more and more as my body further detoxifies from the high-glucose, high-insulin addiction. I do not avoid beer or wine though I am always sure to stay hydrated and again, pay attention to your bodies!

For breakfast, I regularly eat a couple eggs (yolk never excluded), bacon or sausage (uncured) and berries. Some say avoid dairy, I do not and have not, regularly consuming cheeses and heavy cream. I do avoid milk and yogurt (can’t find any yogurt without a minimum of 15 gm of sugar). Remember: fat is ok. For me, low-carb did not mean “high protein” — it meant “high fat”. We’ve all been programmed to be scared of “high fat” — if you need some guidance in getting over your fear of fats, pick up Taubes’ book.

After breaking a fast, eat at least six meals before doing another fast.

Some notes:

While on any initial fasts, be prepared for some folks to think you are completely insane. If you keep it up, you’ll laugh when you find some of these people trying it out themselves a month later. Also, some people may experience headaches while fasting (particularly women). This is your body struggling with the swithover to fat as energy. Feel free to start with smaller fasts (say sixteen hours) before working up to a longer fast. Again, this is very personal — the nuances of insulin-sensitivity differ from person to person. Do what works for you.

If you try this out, please report any results. Questions? Comment below or email me.

Finally, a disclaimer. I am not a doctor. All of the above is for information purposes only. Any experiments you try on yourself are your own responsibility!


I feel good practicing IF and a low-carbohydrate diet. The cravings for things like pizza go away faster than you might think. Excluding easy, filler-type foods makes you a smarter, more creative chef.

Via this regime, nay lifestyle, I’ve gotten back down to a body composition level akin to when I was eighteen, something I had long given up as impossible5. And I’ve done it in only a matter of a couple months.

My results being undeniable, I now have my father-in-law, wife, and brother all practicing this diet, something I now see as a way of life6 that I can maintain indefinitely. My sister-in-law and sister are also dabbling with the diet, too.

Additional Reading:

  • Fat: Mark Twight of Gym Jones talks about how endurance athletes run more efficiently on fat than on carbohydrates.
  • Martin Berkhan on Intermittent Fasting — talks about his history starting with when he was clearly overweight, to uber-skinny model, to experimenting with IF and weight lifting.
  • Fast 5 — a free ebook about fasting on a daily basis, not unlike Martin’s regiment in fast duration. A good introduction to IF.
  • Artificial Sweeteners Cause Energy Disregulation: More compelling (to me) than the arguments that artificial sweeteners cause cancer, is the contention that zero calorie sweeteners confuse our bodies, causing disregulation. I’ve avoided artificial sweeteners for the past two and a half months and haven’t missed them a bit. Note: had to link only to the clip I saved as Art has moved that post offline (or out of public view).
  • Intermittent Fasting: Art Devany is an expert of sorts on the paleo diet (which is low-carb by nature) and evofitness, which is high intensity “power law” training. Here he talks about his approach to IF, which of course, would have fit perfectly with the paleo lifestyle. Art is 70 and looks fantastic. Read his post on mental clarity and fasting.
  • Your belly fat could be making you hungrier: A quote from the research:

    The extra fat we carry around our middle could be making us hungrier, so we eat more, which in turn leads to even more belly fat. Dr. Kaiping Yang and his colleagues at the Lawson Health Research Institute affiliated with The University of Western Ontario found abdominal fat tissue can produce a hormone that stimulates fat cell production. The researchers hope this discovery will change in the way we think about and treat abdominal obesity.

    More from Devany here. Basically, the fat in your abdomen is the last to go — almost fighting for its own existence towards the bitter end!

There are others which I’ll have to point to in the future.


GCBC Despite the name indicating the book is about foods and calories (a diet book), Good Calories, Bad Calories is a fantastic read on the history of research on low-fat and low-carb diets, insulin, weight-loss, pre-Westernized cultures and nutrition, cholesterol, cardiovascular disease, cancer (metabolic syndrome or “diseases of civilization”) and more. If you want to learn all about these topics, you must pick this book up. If you are skeptical about low-carb diets, I implore you to read GCBC. It is a fascinating read at approximately 450 pages (Note: the book is 600 pages, but 150 of them are references!).

1 Watch Taubes lecture on “Big Fat Lies” on Google video here

2 Defined as low quantity or time, high quality or work completed. Volumes could be written (and have been) on this subject. Bodyweight circuits where exercises are performed back to back (See C8B300 for an example) are one form of this. Tabata intervals are another. A Body For Life style cardio session is also popular where you do 2 minutes at Level 5 intensity, then four sessions of one minute each at levels 6, 7, 8, 9 and end with a minute at level 10 and then a minute of cooldown back at level 6 (This adds up to 20 minutes total: 2 warmup, 16 on the four minute intensity cycle, one at peak intensity, and one at cooldown).

3 Therein possibly also lies the answer to a question that arises regarding low-carb diets compared to non-low-carb caloric restriction diets. Research has shown that low-carb dieters can severely restrict calories, achieve significant weight loss, and not be hungry. Comparatively, non-low-carb calorically restricted diets wreak havoc on the dieters making them cranky and typically resulting in all the weight going back on upon ceasing the diet.

4 Many, many people I’ve talked to about this think I’m doing the Atkins diet. If I am, fine. Honestly, I haven’t read Atkins stuff well enough to say if I’m following his protocol or not. I mention the comparison of a fast and the induction phase as a means to point out the connection between fasting and low-carb diets as well as the benefit that fasting provides in terms of speeding along the process.

5 Having tried the aforeblogged Getting back to fighting weight (Post deprecated) Body for Life program and seen results, but only after untold hours in the gym (probably on the order of 100 hours) and pounding three protein shakes per day in addition to three meals.

6 Fasting twice per week is not something you have to do indefinitely. In fact, its too regular to maintain on a permanent basis. Our bodies should be kept on their toes! Periodically going to only fasting once a month would be an option (Or once every other week). Just be sure to mix it up. My guess is that once you try fasting, you’ll find that going on a periodic fast is something you want to do to clear your mind, body, etc. and/or ward off a cold, get over a weekend of gorging, whatever.

7 This diet conforms readily to the way our bodies seem to be genetically engineered by tens of thousands of years of evolution. Hunter/gatherer man wasn’t looking for french fries and rolls! It has only been in the past ten millennia that carbohydrate-dense, processed foods have been available for consumption. Our bodies simply struggle to cope with such a drastic shift in diet from nuts, berries, leafy greens (all slow-to-metabolize carbohydrates on the glycemic index), and meat to breads, rices, potatoes, and sugar which require immense amounts of insulin to regulate.

33 replies on “Better Health via Intermittent Fasting and a Low-Carb Diet”

Hi Justin,

I often hear of no/low carb diets being largely effective as you have highlighted with this post.

And then of course you get the advocates that tell you that you should spike your carb levels throughout a week in order to best optimise fat loss.

Great post and thanks!

Hey Justin,

Great information. I started doing one 24 hour fast a week about 6 weeks ago. So, I have had about 6 full fasts 24 hour fasts now. At first, the fasts were difficult mentally because I figured I should be eating all the time but it sure is amazing how our bodies provide us with energy during a fasted state. I just happened to find your blog by chance today and everything you said here is 100% correct. I’ve read eat stop eat and it has the same basic principles. Great stuff.

I been cutting out as much carbs as I can. I still cheat here and there. I sure do love beer on the weekends. 🙂 So far in 6 weeks, I’ve lost 6 pounds and my strength is basically the same, even a little stronger in some lifts. I’ve been weight training for years, but my diet has always prevented me from showing off all my muscle stored under the fat.

I’m going to keep IFing and might even step it up o 2 – 24 hour fasts a week. I sure feel alot better and my body looks alot better as well. It is so nice to not worry about eating for 24 hours straight.

Keep up the great blog!!

Cheers mate


Thanks for the comment! I’m glad you’re having such success! IFing works, no doubt about it!

Your results are fantastic! It seems to me that many of the people who do IF and follow the kind of diet you outline are very grounded and content overall. IF is something I’ve been doing (usually without realising it) for years because I found that eating most or all of my calories at night made it easier to keep my calories appropriate for the weight I wanted to be.

I’ve migrated to doing 24-30 hr fasts lately and that has been great. I sometimes feel a bit light-headed during the last few hours but doing a short bout of intense exercise helps. It’s amazing that blood sugar does not dip too low during that time. Terrible that there have been so many lies about the ‘bad’ effects of fasting when short term fasts have such positive results. Sadly many people will never try it, or quit after only 1 or 2 tries because they think they’ll always be too hungry or whatever when of course things can get stunningly good after a few sessions.

I used to be a WAPF chapter leader and know the value of REAL food like eggs and cream. I’m looking forward to reading your other posts. 🙂

I still don’t understand how not eating can help build lean tissue. It seems counter-intuitive. But congrats on your success.

Great blog! Tomorrow I am finishing my first ever IF (2 days with no calories other than coffee, tea, etc), and you know what? I feel great…! In fact, I sense that you reconnect with your body in a way that you can’t when it’s numbed by food (or carbs.. or insulin!!).

I am pretty healthy in general and active too – I’d normally do 40 mins of intensive cardio 3 times a week, followed by some good 15 mins of muscle building/weight lifting/pulling each time, and some yoga/pilates twice a week. Also, I am not obsessed with the scales (I haven’t weighted myself for ages).

By letting my body rest from food (and carbs!) I can actually feel the extremely pleasant muscle-repairing sensations in my body. Wonderful stuff! I think that you can fully enjoy the muscle restoration process when you try an IF (or even a few days of “carbs-rehab”).

You know what’s even more curious?? I always wanted to try this, naturally, but didn’t even know the expression “IF” until tonight! Now that is what I call a biological need! All the things I knew instinctively, have been confirmed by this and many other cool sites on the subject.

One question: isn’t the Growth Hormone released only during our sleep, or would we also experience some diurnal spurns when practicing an IF?

Thanks a lot!

Healthy Girl,

So glad you’re reaping the benefits of your first IF! Even as someone who has practiced IF now for two years, I am still sort of amazed at how effective it is at both burning through stored fat and also making me feel great in the process oh and also helping me reprogram bad eating habits! It’s a win on all fronts.

Re: HGH — my understanding is that fasting ramps up various fat mobilizing hormones including HGH, noradrenaline, and adrenaline … I don’t have a reference for that at hand, but I’m 95% sure that is the case. Actually, the reason HGH is probably released while you sleep (just speculating) may be because you’re typically in a little fast while you’re sleeping!

But that’s just a guess.

Hello Justin,I love this blog and have started the IF today. I would just like to know, when you say low carb eating what carbs does that allow me to eat. What carbs should I eat inbetween the fasting?

This has really opened up my insight to what goes on inside of my body.

Thank you


I usually completely avoid bread/flour and starchy foods (like potatoes or beans). Fruits and vegetables are okay (there are exceptions — starchy fruits like bananas I tend to avoid: they aren’t bad, they just are somewhat high in carbs).

Generally, focus on getting plenty of vegetables, protein, fat, and fruits. Keep it natural and you should be good to go!

I’m really happy that I found your blog today. There are a lot of similarities between us and our goals, I’m also 30ish, 180lbs and about 21% body fat, and I just want to lose the fat, not necessarily turn myself into an iron pumping beef machine. I’m also 6 days into ketosis and on my first day of fasting (I’ve had fun with ADF in the past, but not ketosis + ADF). Looking forward to reading some more of your thoughts and experiences.


Love this blog! Just bookmarked it. Im low carb, gonna IF today. I take niacin, l lysine, l arginine, due to the information I read in their ability to give an HGH surge. What are your thoughts or have you read any information about using these supplements with your exercise, diet, and fasting regimen?

Great red. Thanks. I just wanted to leave a comment re my experience…

I’ve been eating Paleo for about 6-9 months, and maintaining a very high protein and fat diet as a consequence. Loving it. Recently, after adjusting whole heartedly to Paleo, i started to contemplate the IF thing, something id been honestly afraid to try even though i know the data and know it suggests that the effectiveness of IF on mental acuity, health, fat loss, and performance are outstanding. It was something hard for me to wrap my head around after being rised on cereals and potatoes my whole life. Anyhow, recently i took the plunge. I am starting slowly however. I do about 3-5, 14-8 hours feats per week. I must say, like you, I’ve noticed an increase in lean musculature, and moreover vie noticed a sense of clarity or what my friend and i (he’s also IF-ing) call a feeling of normal. It is quite amazing, the transition between thinking about food al the time and noticing the associatively conditioned cues to eating, Ike waking up means eating breakfast, even if you aren’t hungry (just stupid). This whole process has made me intimately more familiar and aware of my body and mind and the role both play in my past bad eting habits. I also want to note that my athletic performance even seems to be enhanced. This past week i havew killed my crossfit workouts executing personal records on two out fo 6 days.

Ok, that’s my feelings, great post.

[…] applicable and testable. Soon, I was “self-experimenting.” My experiments began with intermittent fasting (“IF”) and a “paleo” diet, which included a heavy dose of (perhaps misguided) low-carb eating. My health improved markedly […]

I recently started doing fasts and I started with 16 hour fasts follwed by 8 hours of 3 low carb meals. I broke my fast at 2, worked out at 4, and had 2 post workout meals before fasting again. I lost 6 lbs the first week, and felt incredible. I have now graduated to 24 and 30 hour fasts, but these 2 “longer” fasts I typcally only use for a month at a time and switch back to the 16 hour. I love the results. I am going to start using it with all my clients… Check out more info on twitter @eliteironinc.

what about intermittent fasting 24-30 hours and breaking the fast with 2 meals around 100 grams of protein and alot of fat and loads of vegetables(not sure how much fat) all the time with a carb-up every 4-6 days (also i train every second day, usually upper body, with some tabata squats with shadow boxing as a cardio)? i’m having results but if i could speed it up id like some things to add or if im doing anything wrong, since with the changing water retention i dont notice the results some times im a 19 male, around 80kg 12% bodyfat.

Taube’s book is an excellent summary of the science underlying obesity, and also the reason why our current “conventional wisdom” is diametrically opposed to the evidence. It mystifies me why the book isn’t embraced by obesity sufferers in that its premise is that obesity is a disease of fat accumulation not the result of gluttony and sloth.

I’ve learned a lot from DeVany too – I subscribed to his site for a time.

Currently, I’m on a low carb diet and have recently started ADF, although I use a 40 hour fasting interval (I eat dinner every second day). I feel pretty good. I tried ADF a few years ago but wasn’t eating low carb and found that much harder.

I just completed my first fast – 26 hours.

I feel incredibly focused and clear headed. I broke the fast with a teaspoon of organic coconut oil and plan on having some homemade organic chicken broth, some organic chicken (dark meat of course) and a salad with grape seed oil. I’m almost afraid to eat because I feel so energized. I will eat anyway.

I plan to do a 26 hour fast every 4 days, if I can maintain my motivation. I’m starting this for weight loss but plan to continue for the health benefits.

So glad I stumbled across your page! Thanks!

I came across your site after reading Taubes’ GCBC last winter, and today I’ll be doing my 19th 24-hr fast since mid-April. I’ve found IF to be a good way to ratchet down my weight at a gratifyingly rapid rate. I keep a food and exercise log and weigh myself daily, and I lose an average of 3.1 lbs every time I do one of these fasts. I eat a normal low-carb breakfast, then don’t eat again until breakfast the following morning. On the evening of the fasting day I do a fairly intensive 30-minute workout on the treadmill, and most of the time I feel extra-energetic for this workout. Granted, there is a little suffering with hunger & a rumbling stomach in the afternoon & evening, but it’s not bad and it’s actually become pretty easy to fast now. I tend to overeat, especially around the holidays, and I think IF is a great way to quickly recover from those indulgences and feel good again. Thanks for the website!

Hi Justin.

I am excited to try this. Can I use high quality protein shakes containing approx 300 calories as meals on non-fasting days?

Ilove this site

I watched the video “big fat lies” on Google video. The sound was very bad.

Isthere any other place I can get this lecture or can I get a transcript of it?
Thanks in advance

Hey Justin. Love the blog. I have done some studying on IF and low carb for the past couple of years. Medical research and studies indicate that HGH is elevated dramatically during the first couple of hours during sleep. It is also elevated in a fasted state. Many times I do not eat breakfast. Combining the fast during 8 hours of sleep plus several hours before noon, you have your body in a fat burning mode and releasing HGH for many hours. All kinds of great things are happening to you.


Hi, this is all fascinating info. just one question. what is your opinion if you have read or have one about the blood types theory (0 being the oldest and supposed to be more optimized and focused on a high quantity of protein and for meat and milk foods, a being more focused towards veggies and less animal protein, etc), and the IF, paleo approach. p.s. sorry for my english if any mistake, its not my mother tongue.

Great post. I just came across this today while doing more research on IF. I came across fasting in general when I watched the show “Fat, Sick, and Nearly Dead”. Gave a 5 day juice fast a try (didn’t help my ITP, but worth a shot) and lost 8lbs. Since then I’ve been doing IF for two days on and two days off. I usually lose around 4lbs during the two days of fasting. I’m down from 186 to 165. I look better than I did when I got out of basic training!

Hello Justin

Just like all other ppl up above, I am very interested in trying out and I must say that I enjoyed this article soo much mostly because the info is so new to me.

I just have a question about the exercise. I am a Thai boxer (type of kick boxing) and the “exercise” for me means about three hours of super intense activity. If I am on I.F.(fasting), train in the gym, and then eat nothing for the next 10-30 hrs (where usually, I make sure the first thing to eat in the morning is a lot of protein), would that initiate muscle catabolism since my body needs protein to repair?

Thank you!

I think given that kind of volume of training, you probably should have some protein (BCAAs at minimum) prior to your training, but generally, I would be sure to eat after you train like that. You might try sandwiching your training within a “fed” window and then fasting outside of your training windows. Just pay a lot of attention to your body and how this affects you!

When you say “no harmful effects on metabolism so long as you are completing some form of regular high-intensity exercise2.” can you explain what harm and why? And what would you advise if high intensity exercise isn’t possible due to illness/disability? I used to regularly ‘fast’ from about 7pm until about 3pm but I didn’t realise this had a name, it was simply because I recognised that the earlier I started eating the hungrier I would get. All went a bit haywire when I fell ill and I put on 5 stone but being back on the lc I started doing this again and now you’ve got me worried 🙁

I think you’ll be fine doing what you’re proposing — the “harmful effects” I was thinking of had more to do with longer-term fasting — like 30hrs or longer. It’s mainly that the longer you fast, the more your body is going to tap into lean tissue for energy (even if only a little bit). The workouts basically prime the pump so that when you eat, nutrients replenish lean tissue.

That’s my layperson understanding.

Hi Justin, found this page after reading your section on glycogen stores/water loss, etc. Excellent reading. I have been on a low carb eating plan for just over 4 weeks, took up power walking and do resistence training at home (I use a litre bottle of bacardi as my weight!!! – just to remind myself of how much control I have now!) I have lost 6.5kgs. I, like some of the others, was wary of fasting, but am very happy to have read this article and I plan to start this (frankly, since cutting out the carbs I feel satiated just on protein. I have just turned 58 and female. In addition to the wonderful feeling of liberation from glucose I would like to point out a few extras (for the women in your family). I have noticed that my skin tone has become more even, texture is softer, no sagging of skin from fat loss – none of that ‘drawn’ look, less hair falling (when brushing/showering)stronger nails, less tarter on my teeth, more alert mentally – to mention only a few benefits. This one is for you; I have ‘Total’ greek yogurt 0% – its delicious, creamy and has 4g sugar per 100g. – Thank you so much for the information above, I intend to start my first fast tomorrow.

Hi! I just started my 1st 24 hr IF last weekend last meal was 7pm friday then ate 7pm the following day.
Have been on a low carb diet for more than a year, practically eliminated eating rice and junk food from my diet. I do cardio: stationary bike exercise atleast 20 mins daily, pushups/pullups, and few runs. From being 168 lbs, now I’m 134 lbs. Pants size from 34 waist to size 30, also shirt size is now Small from Large.
The reason I tried this diet is I would like to lose stubborn belly and back fats.

Question would be: with my objectives, Is it ok to do once a week 24 hr fast?

Ps: I’m not much of a weights person.

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