Daily Intermittent Fasting: What You Need to Know

I’ve had a couple of questions come down the pipes as of late: do I really eat one meal a day? Isn’t it bad to go without food for so long? And – here’s my favorite – isn’t breakfast the most important meal of the day?

For that last one, at least, I have an easy answer: nope. Judging by the kid’s breakfast a few tables over at this hotel, in fact, I’m inclined to throw down a definitive statement on the subject once and for all. Are you ready for this? It’s a big one.

If your ‘breakfast’ consists of three cookies, a bowl of oatmeal, and then a bowl of cereal, breakfast is the absolute worst meal of the day.

When it comes to daily intermittent fasting, though, things aren’t cut quite as clear. There’s a solid chunk of info you need to digest (breaking news: fasting requires digestion!) before diving in, so let’s get cracking. This won’t be the last post about fasting you’ll ever see on 3NL, but it might just be the most comprehensive: a chance to clear up a few misconceptions about the process, and an opportunity to clarify just how my own approach to fasting might be able to help you too.

What Daily Intermittent Fasting Is

It’s a tool.

One more time so it’ll stick: intermittent fasting is a tool. It’s a tool in your toolbox to further fine tweak your approach to food, and it’s a chance for sensible, practical-minded folks like yourself to enjoy the occasional indulgence without the accompany guilt, depression, cereal binge, etc. It’s an easy way, too, to practice a little caloric restriction without going out of your mind, which can help tremendously once you’ve dieted down to near single-digit body fat percentage.

What Daily Intermittent Fasting Is Not

Intermittent fasting is not a necessity. At no point in your weight loss journey should you feel compelled to try it, and at no point should your slavish dedication to twice-daily meals ever interfere with the quality of your life. Mark Sisson, the Grokfather himself, maintains good health (let alone an enviable physique!) while still eating three meals daily, and brains far wrinklier than mine have voiced valid concerns about recommending fasting to people of all shapes, sizes, metabolic conditions, etc.

The point of this article, accordingly, is not to make any whole-sale recommendations. Fasting might not work for you. I think it’s worth a shot, certainly, if you’re metabolically sound. The health advantages far outweigh any initial discomfort, but there’s a lot that can be said about focusing your energy elsewhere: eliminating snacks, pushing your plate away when you’re actually full, and so forth, all of which are valid ‘techniques’ to keep yourself satiated, happy, and increasingly lean.

With that in mind, let’s break down the process a bit further and see how well it might apply to you.

The Benefits of Fasting

Three big ones come to mind: reduced caloric intake, autophagy, and an increase in stubburn fat burning once you get further into the fast.

The former is self-explanatory, but I think it’s a point worth highlighting. The idea of counting calories isn’t a popular one in the Paleo camp, and I’ve argued against it myself given the obsessive approach toward food it can often become synonymous with. One of daily intermittent fasting’s key perks, then, is to further eliminate the need for numbers.

Eating one or two meals a day, to put on my obvious hat, equates to eating less. You’re effectively lowering the number of calories you ingest on a daily basis, which – unsurprisingly! – can lead to enhanced fat loss over the course of the week. This, I’ve decided, is a good thing.

The next benefit, autophagy, is a crucial part of our intracellular immune system. To quote Paul Jaminet, the exceedingly kind man behind the Perfect Health Diet:

“When resources are abundant, cells allow aged organelles and junk proteins to accumulate. When resources are scarce, they turn on autophagy and digest unnecessary components, recycling the resources. Autophagy is the dominant innate immune mechanism inside cells – the primary way cells kill bacteria and viruses. Autophagy also recycles damaged mitochondria, which can be digested, enabling remaining healthy mitochondria to multiply. The result is a healthier mitochondrial population.”

A scarcity of resources, unsurprisingly, comes as a result of fasting.

Regarding the last benefit, I’ll leave most of the verbiage to Martin Berkhan: his excellent article on Intermittent Fasting and Stubborn Fat Loss goes into great detail on the advantages of short-term fasting for the oxidization (burning!) of subcutaneous fat. To paraphrase: 12-18 hours of fasting creates an ideal environment for your body to burn that stubborn fat, the kind which likes to linger around your gut and effectively ruin your quest for abs.

You might say I’m familiar with it.

A Brief Note for Starvation Mode

Starvation mode, or at least the popular conception of it, is utter nonsense. I wanted to use a stronger word there, admittedly, but I think you get the gist.

That’s not to say starvation mode, a period in which your body consumes its stored muscle mass to produce glucose (and, y’know, survive), does not exist – far from it. It is to say, however, that our concerns about starvation mode kicking in every single time we go three hours without food are ridiculous, and that established studies on the subject suggest starvation mode doesn’t even kick in until you pass 60 hours without food.

One more time: sixty hours. We’re talking sixteen to twenty-four hour fasts, here, which are not nearly lengthy enough for starvation mode to even think of kicking in. It just so happens, too, that there are ways to preserve lean muscle mass even during those lengthy, multi-day fasts. Those are a bit beyond the scope of this article, but if there’s interest then I’ll cover them at later date. When it comes to your daily intermittent fasting, however, don’t stress – starvation mode is not a concern.

How to Fast

Don’t eat.

Before you start pitching (organic, locally-grown) tomatoes my direction, however, let’s break it down like this: there are, to my current knowledge, four ‘popular’ ways of incorporating fasting, all of which will be covered briefly below.

1.Daily Intermittent Fasting: a 16/8, as it is informally known, where you condense your eating into a period of eight hours each day. This is my preferred method, personally speaking, and often translates to one meal around noonish and another six or seven hours later. I don’t eat outside the window (normally!), and I pass the morning hours with delicious, appetite-suppressing caffeine.

2. Alternate Day Fasting: wherein you eat three square meals on one day, ending with your last meal around 6 or 7pm, and then fast until that same time the next day. This is the method offered by Brad Pilon in his (superb!) book, Eat Stop Eat, and it’s a method that works for a lot of the same reasons as the above – caloric restriction over the long run.

3. The Long Fast: wherein you fast for a day or two each week, or three or four days each month. Those numbers are highly variable, but the core idea remains the same – go without food for a day or two every so often, and proceed to eat normally at all other times.

4. Eat When You’re Hungry: This isn’t so much a fasting ‘technique,’ I suppose, as it is an attitude towards food. Without going into every emotional complexity attached to what we eat, I think it’s safe to say that the majority of us don’t have a great relationship with food, eating when we’re bored/tired/sad and only rarely when we’re actually hungry. How many times have you eaten a meal out of some sense of strange obligation over any actual desire for food? An alternative approach, then, resonates with logic above all else: eat when you’re hungry, stop when you’re full, and don’t stress a thing.

I won’t bother trying to rank them. They all work, I suspect, and for similar reasons, though the different nature of each approach might just help you find a way to incorporate fasting into your otherwise chaotic schedule.

My personal preference lays with #1, the 16/8, since I rarely feel like getting up a few minutes earlier in the morning in order to cook something up. I feel it’s the easiest to incorporate into a work schedule, too, in that it still allows you to enjoy a lunch with coworkers and a dinner meal with your family/friends/pets. It might seem strange to skip breakfast, but take heart: who says you can’t have eggs with dinner?

The First Week of Fasting

You’ve decided to try fasting, then. Good for you! Want to know what to expect?

To quote John Nguyen, my personal favorite faster: “You will be hungry.” Just how much will vary on an individual basis, but I’d expect at some some stomach rumblings to start with, especially since your body might be accustomed to thrice-daily meals. I talk at length about the ‘hunger’ hormone, Ghrelin, in Roots, but I’ll keep it brief here and say that it’ll take about a week or two to retrain it, after which you’ll find it far easier to skip – using 16/8 as an example – a morning meal.

You’ll find the process of fasting far easier, too, if you’ve been on a low-carb diet before starting. Going low-carb for a length of time has a few perks: it helps the body adjust to burning stored fat for energy, which is nice, but also instigates ketosis within the body. You’re likely familiar with the term, but ketosis describes a state where ketones – an alternative form of energy that the body can grow to utilize – are produced by the liver to compensate for the lack of glucose (carbs!) coming in from your diet. The presence of ketones, coincidentially, leads to decreased appetite, which can make your initial forays into fasting seem far easier than expected.

All that said, allow me another repetition: you will be hungry. My first week of skipping breakfast came with some intense hunger pangs, but there’s something to be said for perseverence. I stuck with it, drank a lot of water whenever my stomach acted up, and emerged where I am now on the other side – able to skip any meal freely, and often passing the hours between about 7am and noon without any hunger pangs at all.

And a Few Final Thoughts

Again: intermittent fasting is a tool. It’s one that I think is worth experimenting with, given the myriad benefits that emerge from skipping a few meals, and I think it’s an effective fat-burning strategy if you’re as terribly, terribly vain as the author of this article. The words above, I hope, will give you a good base to start with as you dive further into the subject, but here are a couple of other links that I think every would-be daily intermittent faster should read:

1. The Lean Saloon
2. Top Ten Fasting Myths Debunked
3. Intermittent Fasting, Set-Point, and Leptin

The latter two dive into the nitty-gritty of fasting: why it works, what it does to the body, etc. The first link emphasizes a simpler approach to the subject, advocating a better way to approach our daily food intake. I can’t overexaggerate the impact that The Lean Saloon has had on my own approach to food, and I’m happy to report, too, that I scored an interview with its owner, John Nguyen, back in the early months of Three New Leaves. Read the first part here: Living Lean: An Interview with John Ngyuen.

If you have any questions, please leave them as a comment below. Thanks!


  1. eva says:

    Mmkay, overall I agree, but a note on the 60 hour thing: as a person who nearly died from anorexia, I can say that it is definitely possible to eat every 12 hours and still starve to death. But, you do have to do it *persistently* rather than *intermittently*.

    • Matt Madeiro says:

      A great point, eva!

      Like I wrote above, fasting is a tool best utilized by the metabolically sound — the kind of people who can go longer than 12 hours without starving to death. There’s a distinction worth being made, of course, if you’re not in that group, but I don’t think it’s too crazy to say that those are special cases more so than the norm.

      That said, there’s value in clarity. :) Thanks for that!

  2. Suz Paleo Australia says:

    Great post. The first thing anyone says to me when I mention it is about how I’ll go into “starvation mode”, very annoying!

  3. eva says:

    Well, people with eating disorders do THINK they are metabolically sound;)

  4. Matthew says:

    I’ve been doing the “16/8″ thing for a while (just never liked breakfast), but I’ve only recently started eating primal (I bought Mark Sisson’s new book over the weekend!), so right now (at noon) I’m HUNGRY! I suspect it will get a little better, though, as I get more used to being away from the carbs …

    Also, talk to me, if you will, about your comments on caffeine. I’m a HUGE fan of my morning coffee, but I’m trying to cut back because of my understanding of the relationship between caffeine and insulin production. Any thoughts?

    Thanks for the post!

  5. Vic Magary says:

    Outside of my morning coffee with the admitted occasional cream (yep, picked up my taste for cream in the coffee from the Grokfather himself), I almost never eat breakfast. And many thanks for calling out the “starvation mode” fears. I was recently asked about that in an interview and said unless you are at mid to low single digit body fat, I don’t think it should be a concern.

  6. Russ says:

    I don’t fast regularly, or even often for that matter, but I definitely notice a correlation between my ability to skip meals (whether intentional or unintentional) and what I’ve been eating recently. If I’m eating super healthy, mostly whole, organic foods, I can skip a meal no problem with no hunger pangs, but if I go out and eat junk for dinner, I am starving right away when I wake up in the morning. So I definitely agree with what you said about going low carb making it easier. But I also seem to get hungry more often if I’m eating more meat. When I tend towards no meat, no dairy, I rarely get excessive hunger. Interesting stuff!

  7. mike fareri says:

    hey buddy, i thought you were kinda nutty when i first heard you fasted but i think i’m going to give 16/8 a try. doesn’t seem too difficult at all. i don’t get up early enough to cook breakfast mon-fri and usually end up snacking on jerky or seeds in the morning. i’m sure i can cut that out until my normal lunch time which is around 1:30-2. my usually dinner time is about 7-7:30 so it will work out well. i’m no fan of coffee so delicious water will have to help me get by. i’m going to start tomorrow, i’ll let you know how it goes.


  8. Ben says:

    I tend to do the 18/6 or 16/8 thing a couple of times a week – and I can definitely feel it the days after I’ve done it (in a good way). I’ll typically do it when I’m not doing crossfit at 6:00 am, if I have a morning workout I eat breakfast probably 3/4 of the time, and I don’t notice any negative impacts with recovery or anything if I skip.

    Also from personal experience – eating primal/paleo whatever you want to call it made all the difference when it came to IF for me. When I started (again – only 2-3 days a week not every day) I had no issues with hunger in the morning.

    “It just so happens, too, that there are ways to preserve lean muscle mass even during those lengthy, multi-day fasts.” – I’d love to see your article on this. My longest fasts have gone about 24 hours – usually I eat at the end not because I’m starving but I feel I probably ‘should’. I’m definitely interested in trying something a little longer.

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  10. Tyler says:

    I’d love to see more on that, too, Ben.

    I’ve heard good things about Branched Chain Amino Acid supplements in a fasted state helping to preserve lean mass. I assume this has to do with gluconeogenesis and the BCAA being utilized before the breakdown of muscle..? Not quite sure, as it’s just what I suspect.

    Speaking of which, how does BCAA play into fasts? Is it still technically a fast?

    And what of coconut oil? I know that the fatty acids help streamline ketosis, but how does a tablespoon of that while fasting affect it? Is the fast then disrupted?

    Same thoughts with cream in coffee. I typically drink it black, but I’m wondering how much caloric intake is required before a fast is no longer a fast.

    Thanks for the article and great resources! I will be reading the links you left.

  11. Mia says:

    Have you ever heard of people skipping lunch and fasting that way, only eating breakfast & dinner? I only ask because I LOVE breakfast as a meal, drinking my smoothie in the morning sun is a great ritual I’d hate to lose. And dinner is a social thing. Would it work, having 2x 11 hour fasts per day?

    My other option is the eat stop eat method. Which is also appealling…

    • Matt Madeiro says:

      Hey Mia! Glad to see you’re still reading. :)

      That would definitely work as a fasting routine. I’ll be honest and say it’s probably not ideal, given that you need to go 16-18 hours fasted before the body really starts burning through those stubborn fat deposits, but as a means of caloric restriction, skipping lunch will still work just fine. :)

      So give it a try! ESE is a great option too, but just experiment and see what works best for both your body and your schedule. :)

  12. Dom says:

    This article has really cleared up a lot of confusion I had about daily fasting. I have been on the 16/8 fast for about 5 years, but I have noticed many people tend to get alarmed when they find out I am vegetarian, on top of fasting. Would you say it is still healthy for a vegetarian teenager such as myself?

    • Matt Madeiro says:

      My concerns for your health, Dom, don’t have much to do with fasting — I’m more worried about the lack of animal products in your diet instead. :)

      That said, I can see where some people would be concerned. If you’re eating mainly veggies in your diet, you’re possibly not getting a lot of calories from two meals alone, which in the long term (i.e. caloric restriction like that over the period of a month or two) tends to negatively affect some crucial hormones in the body. I’d also be concerned about the lack of healthy fats in your diet, but again that comes back to animal consumption, and I’m going to go out on a limb here and assume you have a solid reason for your decision to avoid them. :)

      Long story short? It depends on what and how much you currently eat. By eliminating most protein you’re seeing some benefits of autophagy, which is a perk, but make sure you’re still getting your maintenance calories in during those two meals. If you’re operating on heavy caloric restriction, well, it might be time to look into refeeding.

  13. Mia says:

    Hi Matt! Yup, still around, although not as often as I’d like due to life and it’s inherent craziness lately. :) My health and metabolism have improved heaps recently, so I thought it was time to give fasting another shot. For the last week I’ve been trying the Fast 5 method (19/5 fast) purely because it means I get to be lazy & not pack a lunch for work! It’s just too tempting to pass up. Smoothie at night isn’t such a bad thing. :) My first 24 hour fast was east as (gluten free, Paleo friendly) pie, but then once I switch to daily fasts (19 hour ones) I started to really get hungry. It’s been an interesting experiment! It also makes me more conscious of what I eat, cos if Im only having one proper meal a day, I want it to be a good one.

    Autophagy & autoimmune disease sounds like an interesting experiment, so I will let you know how I go! xx

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  18. Belinda says:

    What do you think of grazing instead of having only two meals. I am more comfortable having a lot of little snacks during the day. For instance, I would like to break the fast around 10:30 by having an orange, toast with butter and jam and tea but then around 1 have a small lunch and around 3 have a few almonds and a few dried apricot halves or maybe hummus, carrots and a few pita chips then have dinner by 6:30 and eat nothing until the morning. Is there a reason to confine your eating to only two meals?