Intermittent Fasting: The 16/8, 5/2, Eat-Stop-Eat and 24 Hour Fast Benefits


“Sometimes the magic isn’t in what you’re eating, it’s in what’s going on in your body when you’re not.”

– Mark Sisson

Anytime my dog Jacko doesn’t feel well, he won’t eat for a few days.

I got a stomach virus once and I couldn’t eat for a week. Once I recovered, I felt better than I’ve ever felt in my adult life.  

Most major religions include a form of restricting food in order to achieve mental and spiritual clarity. Jesus and Buddha apparently both did it for like, 40 days.

All of these instances are examples of fasting.

Fasting is something we all, including my dog, naturally gravitate to when we’re not well. We stop eating so our bodies can rest and heal. And in the case of religion, to clear distractions and sharpen the mind and spirit.

It’s become incredibly popular lately in the wellness world. The widespread adoption of ‘intermittent fasting”, or ‘IF’ by the paleo and keto communities has got everybody buzzing about it. So today, I thought I’d dive in and explore what exactly Intermittent Fasting (IF) is all about.

Here’s what we’ll be looking into:

  • What is intermittent fasting?
  • What are the benefits?
  • How does one do it?
  • Is it safe for everyone?
  • Should I try it too?

What is intermittent fasting?

IF is an eating pattern in which you cycle between periods of eating and periods of not eating. We say “eating pattern” because it’s not really a diet. It doesn’t focus on what you’re eating, but on when you’re eating. Or, more importantly, when you’re not eating. Though, it’s certainly easier and healthier when you’re eating a certain way, but we’ll get to that in a minute.

IF is essentially the conscious decision to prolong the amount of time between two meals once in a while.

Most of us technically fast every, single day, when we sleep at night. That’s where breakfast gets its name: break-fast. So IF is basically just prolonging that naturally built-in fasting time a bit longer, say until noon.

Some popular forms of IF are:

  • The 16/8 Method – in which you fast for 16 hours per day and only eat meals within an 8-hour window (for example, 12 pm and 7 pm). You could also refer to this by its more technical name: skipping breakfast. Joel was like “Oh, apparently I’ve been intermittent fasting by accident half of my life.”
  • The Eat-Stop-Eat Method – in which you fast for a full 24 hours once or twice a week. This seems more intense to me and would probably require some serious prepping to be successful and healthy.
  • The 5:2 Method – Two days a week (non-consecutive) you’d reduce calories to about 500-600 for the day, and then eat normally the other five days. This also doesn’t really sound fun to me.

There are other ways to do it but, there aren’t really any hard and fast rules.

What are the benefits of intermittent fasting?

It seems our natural inclination toward fasting when unwell is because our bodies are smarter than us. Many benefits arise from some combination of the changes at the cellular level when fasting. Changes around:

Insulin Levels

We know insulin plays a huge role in our overall health and weight, and fasting seems to improve insulin sensitivity while dramatically reducing our overall levels. This allows us to release stored fat more efficiently, making it a powerful weight loss tool.

Gene Expression

Seems as though there is evidence suggesting that two dietary interventions, caloric restriction (CR) and intermittent fasting (IF), can prolong the health-span of the nervous system by impinging upon fundamental metabolic and cellular signaling pathways that regulate life-span.”

(What’s that now?) Looks like IF could potentially protect the body and brain from degenerative issues, such as Alzheimer’s and Parkinson’s diseases, that typically arise as we become more vulnerable to them due to aging.

Growth Hormone

Fasting naturally increases the levels of human growth hormone. This has a long list of benefits including fat loss, muscle gain, stronger bones, reduced risk of cardiovascular disease, improved mood and cognitive performance, and improved sleep.

Cellular Repair

When we’re fasting, our bodies initiate crucial cellular repair mechanisms, including autophagy.

[Autophagy has been recognized as a crucial defense mechanism against malignancy, infection and neurodegenerative diseases. Abrogation of autophagy in neurons can lead to neurodegenerative disease and autophagy may play a role in the development of Alzheimer’s disease, indeed, enhancement of autophagy has been proposed as one possible treatment for this coming plague.]

Basically, fasting allows your body to stop digesting – which uses an enormous amount of energy – and switch focus to these crucial repair processes. When these repair processes are prevented over a lifetime – because we’re always eating – bad shit can happen.

Other Potential Benefits

The metabolic changes in the body due to IF might lead to other benefits as well. Though more research is needed, what’s available so far, has shown promising results around:

Our Paleo Ancestors

Since the inhabitants of our pre-agricultural family trees lived as hunter-gatherers, they only ate if they’d managed to kill or find something edible. This lead to naturally induced intermittent fasting. They simply weren’t eating three square meals a day and snacking in between, like we do. They were most likely eating a whole bunch when they had it, and going for periods without any at all when they didn’t. This meant that in between feasts, their bodies had adequate time to regulate hormones and commence crucial cellular repairs. Something we don’t allow ourselves much these days.

Many a paleo expert sees this eating pattern as an important clue as to why we don’t see much evidence of our ancestors experiencing the chronic, degenerative and metabolic disorders that are killing us today.

Sure, they probably had to overcome many brutal challenges to make it to old age in the first place, but, once they got there, they didn’t seem to die of heart disease or lose their marbles.

How does one intermittently fast?

As noted above, you could just skip breakfast.

No, really, it’s that simple. Most novices at IF start with expanding the amount of time per day that they don’t eat, and shrinking the window in which they do.

The rules are sort of fluid though. You’ll see some folks talking about sipping on fatty coffee in lieu of breakfast and calling it fasting. You’ll see some say nothing but water is allowed. Some people only eat one meal per day. Some fit all three, plus snacks into an 8-hour window.

It seems to me though, that part of the success of intermittent fasting is also found in the reduction of calories. Meaning that in reducing the overall time you can eat during the day, this should naturally reduce your overall calorie intake in conjunction with the break from digestion. It’s important to give your body longer to get past digesting and initiate repair, but also fewer calories to deal with in the first place.

How to Not Feel Awful While You Fast

Once you start researching IF, you’ll notice that it’s a tool most popularly used with the paleo, keto, low-carb community. And this makes sense to me. Because it’s a whole hell of a lot harder to do any type of fast if you’re diving straight in from a blood sugar roller coaster.

I’ve noticed that if I’ve just eaten paleo for a day or two, I can wake up and not feel hungry for a long time. Sometimes I’ll just wait to feel hungry before eating anyway inadvertently IF’in’. But if I’ve been flailing about eating whatever, I wake up hangry and have to eat immediately.

Eating a diet rich in vegetables, healthy fats and proteins and low in sugars, carbs and grains, is a great way to naturally segway into IF. I notice that most days, after a hearty, paleo-style breakfast and a big salad packed with healthy fats for lunch, I’m naturally and honestly not hungry when dinner time rolls around. This is my favorite way of intermittent fasting because it’s just a natural byproduct of eating healthy for me. These are also the days when I find myself sleeping more soundly, waking up easier and losing weight quickly.

Going from the Standard American Diet (high in processed foods, sugar and refined carbs) to intermittent fasting is likely going to be extremely difficult and uncomfortable though, as would trying to fast while still eating it. When I’m talking about intermittent fasting here, I’m assuming that you’re not going to do it by eating pizza and cupcakes but rather, as an extension of a healthy, nutrient-dense diet.

If you’re interested in checking out the benefits of it, but aren’t eating what you’d call “healthy” yet, it might make sense to shift gears to paleo first.

Check out Mark Sisson, Rob Wolff, Whole30, The Ultimate Paleo Guide or Paleo Leap for some guidance on that lifestyle. There is solid evidence that it’s great for everybody!

An Important Note

IF should come naturally and feel good. It shouldn’t be an uncomfortable, stressful struggle to achieve. There’s some evidence that shows men and women respond to it differently and, like anything else in the world of nutrition and wellness, everyone is different and nothing works for all. It’s important to be honest with yourself about why you’re doing it and how you feel. Because if it’s making you feel terrible, you’re probably not getting the benefits out of it anyway.

Which brings me to my next topic…

Is Intermittent Fasting Safe for Everyone?

Short answer = ABSOLUTELY NOT.

Okay, let’s discuss the fact that intermittent fasting is definitely not for everyone. Intermittent fasting is most likely not a good idea – or could potentially be flat-out dangerous – for any of the following folks:

  • Children
  • The elderly
  • Women who are trying to get pregnant
  • Women who are pregnant or breastfeeding
  • People who are seriously ill
  • People with chronic heart or kidney disease
  • People with diabetes
  • Anyone with a history of disordered eating

Though fasting can be a powerful healing tool, to do it for any medical reason would require the careful assistance and guidance of medical professionals. You definitely don’t want to mess around here. And for those with a history of disordered eating, it could potentially be a slippery slope.

IF can be a great tool for otherwise emotionally and physically healthy people to feel better and lose weight, but if used improperly and under the wrong circumstances, it can be dangerous.

Is IF right for you?

I have no idea. In order to find out, you might want to ask yourself a few questions:

  • Why do I want to try it?
  • Am I healthy to begin with? (See list above of who it’s definitely not for)
  • Am I even remotely fat-adapted?
  • What does my current diet look like?
  • Would it be part of an overall healthy lifestyle? Or am I looking for a silver bullet?

Taking some time to think this through is a great idea. Intermittent fasting is definitely not for everyone. But, under the right circumstances and for the right reasons, it can be a powerful way to help you feel your best.

What about you? Have you been thinking about trying it out? Have you ever experimented with IF or any type of fasting? What did you notice?


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