It’s curious how not eating can spark so many questions and debates. A practice born out of necessity for our ancestors, fasting for long stretches happened when weather or circumstance hampered hunting and gathering, or for shorter periods while on the hunt or foraging.
As food has become readily available and abundant in many countries, our near-constant state of food arousal can dull the hormonal drivers that regulate appetite and, ironically, lead us to want to counteract the overabundance with some restriction. When we eat too much too often, we get the natural inclination to push back from the table and vow not to consume another bite for a (possibly long) while.
Fasting, particularly intermittent fasting, is gaining popularity now as a weight loss and weight management tool. As some celebrities proclaim that intermittent fasting is one of their “secrets” to their hard Hollywood-worthy bods, more and more people will be keen to latch on. We compiled a list of our greatest hits on fasting and intermittent fasting to provide education and context around how intermittent fasting works, reasons you may want to try it, reasons you may not want to try it, and considerations for athletes who want to fast.
First, let’s start with the basics. Before making any changes to your eating (or non-eating) habits, it’s important to understand:
Do the effects of fasting differ for men and women? What are the most common things people get wrong about fasting? Is fasting an effective tool for weight loss? We answer those questions, and more, in the following articles.
Fasting can be really beneficial to those who are trying to lose fat. Yes, that’s fat and not weight. Unlike some other kinds of weight-loss methods, which result in loss of water weight or muscle mass, fasting can effectively get rid of fat.
There is no one way to do IF. The only real guideline is that, as always, the food you eat should be healthy. (It’s pretty clear how we choose to characterize that.) In addition to the substantial health benefits, the simplicity and flexibility are what draw people to IF.
Dry fasting is going without both food and fluid. That means no coffee, no tea, no broth, and no water or liquid of any kind (except the saliva you manage to produce). It’s an extreme type of fast whose fans and practitioners are adamant that it can resolve serious health issues. But does it? Is it safe? And what kind of research is available on it?
Both fasting and carb-restriction appear to operate along similar physiological pathways. Both lower carbs. Both increase fat-adaptation. Both have the potential to get you into ketosis. Both lower insulin and blood sugar. But is one better than the other?
If you’re making fasting mistakes, you might never accomplish the benefits you were hoping for. Before you throw in the towel, I want to help you identify some possible fasting pitfalls you might not be aware of and also help you avoid them.
Fasting is one way to have your cake and eat it too. Beyond the already proven benefits of a Primal Blueprint low-carb lifestyle, fasting once in a while seems to offer many of the same benefits of calorie restriction—you know, stuff like increased longevity, neuroprotection, increased insulin sensitivity, stronger resistance to stress, some cool effects on endogenous hormone production, increased mental clarity, plus more—but without the active, agonizing restriction.
With fasting, perhaps the most important variable to consider is your biological sex. This really does make intuitive sense. Biology cares most about your fertility. Can you reproduce? Can you produce healthy offspring that survive to do the same? These things come first. And from that perspective, a woman’s situation is more precarious than a man’s.
Primal folks who are losing weight or looking to lose a bit more, and getting the right lifestyle changes enacted (sleep, exercise, sex, leisure, rest, relaxation, mental stimulation) should definitely try fasting. They will likely flourish.
How do you know if your fasting regimen may be slipping into the grey area of potential orthorexia or disordered eating? We can’t diagnose anyone in an article, of course, but there are signs to watch out for if you have personal concerns or worries about others.
Anytime you attempt a “radical” health practice like not eating, it helps to have a good reason to do it. That will not only give you something to aim for, but it will ensure you actually have a physiological justification for your experiment. Never go in blind. What are some of the specific scenarios and conditions where fasting makes the most sense?
If fasting for more than three days sounds riskier than just skipping breakfast, you’re right. Long fasts can get you into trouble. They’re a big commitment. You shouldn’t just stumble into one because it sounds interesting or some guy on your Twitter feed wrote about it.
It’s the nature of many beings—particularly those with weight-loss goals, it seems—to want to know what the “rules” are so they can look for the loopholes to bend them. It’s no surprise that the top-performing article last year on Mark’s Daily Apple was “Does Coffee Break a Fast?” Consequently, we followed up with an article about whether bone broth breaks a fast because we received additional questions. Then people wanted to know about supplements—should they be taken while fasting? We then created a definitive guide to what breaks a fast. If there’s any other liquid, leaf, pill, stone, or twig we neglected to examine, let us know in the comments section.
Most people aren’t fasting to be able to brag about eating no calories for X number of days. They fast for shorter (often intermittent) periods of time for specific health benefits. It’s entirely possible that bone broth “breaks a fast” but allows many of the benefits we associate with fasting to occur.
Does black coffee break a fast? Put another way… Does coffee interfere with the benefits we’re seeking from a fast? Depends on the benefits you’re seeking (and what you put in the coffee).
Let’s look at some of the most common benefits first and if/how coffee affects them.
Does fish oil break a fast? What about my multivitamin, protein powder, collagen, or melatonin? Mark delves into the research to provide definitive answers.
One of the most common questions I get is “Does [x] break a fast?”
What they’re really inquiring about is: “Does this interfere with, negate, or nullify the benefits of fasting?” Let’s go through the most popular queries one by one and figure out how each one affects an intermittent fast.
Does fasting before and during workouts confer any performance perks or additional fat-burning benefits? Should athletes fast before every session, or only specific types of workouts? What are the potential drawbacks to fasting for athletes? Let’s go.
What are my specific recommendations for athletes who wish to explore intermittent fasting? I’ve got 12… plus some details about my own fasting and workout routine.
Sometimes, high stress is exactly what we need to progress—a few heavy sets of squats, some rounds on the Airdyne, a killer CrossFit workout—as long as you can recover from it. A major modulator of our stress is the amount of food we have coming in. At least in theory, exercising in a fasted state could provoke a powerful adaptive response that athletes would find helpful. So, does it stack up? What exactly can intermittent fasting offer athletes?
To some, the idea of working out without “carbing up” or doing the pre-workout protein shake is unthinkable. To others, fasted workouts are sacred tools, the perfect antidote to modern decrepitude. Where does the truth lie?
That’s it for today, folks. Thanks for reading, take care, and leave a comment below if there are more questions you have about IF!