Lose Fat. Fast!, provided some background on dieting in general and made the modest proposal that fasting may be the best weight loss solution for you. In this post I discuss some of the myths and research-backed benefits of fasting. Before proceeding, however, I want to make it clear that I’m not some kind of fasting-zealot. It’s worked for me but it’s not for everyone. If you would like to see if it’s right for you, read this post and its follow-up and you’ll get a good idea of what you’re getting into. If you’re convinced fasting is not a solution for you, please don’t confuse my enthusiasm for the approach as disdain for other nutrition strategies. The best diet is the one that gives you the results you want, helps you maintain those results indefinitely and fits seamlessly within your lifestyle. And I’m prepared to discuss them all.
Myths About Fasting
- My body will start consuming muscle as fuel – This is true if you’re starving but there is a physiological difference between your body being in a starved state vs. a fasted state. Your body will not go into starvation mode if you fast for 24 hours. The exception is if your body fat percentage is in the low to middle single digits. Then you might already be starving.
- It will slow my metabolism – Technically true because the act of digestion adds to your metabolic rate. But, it represents such a small part that you easily overcome it by the reduction in calories consumed. However, once you start losing weight, your metabolism decreases. This is true with any weight loss whether it comes from fasting or not. There is no research that supports the idea that intermittent fasting decreases your metabolism.
- My mind isn’t as sharp when I haven’t eaten – Research has shown no significant difference in cognitive ability between adults in a fasted state vs. those who are fed. In those same studies adults on calorie restricted diets tend to perform lower on cognitive tests than either the fasted or fed group. Scientists do not yet know why this is the case but they believe it is mostly that the long-term dieters are grumpy. Really. My own experience is that I am often at my sharpest and most creative on fast days. Meanwhile, we all know that food coma sensation when we come back to work after a big lunch.
- It will cause a drop in my blood sugar – If you’re diabetic or truly hypoglycemic, you need to worry about this. While diabetes rates continue to increase, very few people are truly hypoglycemic. And for those of us who are neither, your body has a beautiful mechanism to make sure your blood sugar is where it needs to be. One of those mechanisms involves burning fat for fuel.
- My hormones will get out of whack – Again, your body is perfectly designed to manage fed and fasted states. No hormones will be damaged in the process. NOTE: In subsequent research after I originally wrote this women may be more subject to hormones getting out of whack due to intermittent fasting than men. Check with your doctor.
- I won’t be able to exercise – This is only true if you’re about to do an extended period of aerobic or resistance exercise. But if you’re not going marathon distances or doing an hour’s worth of lifting, you will suffer no adverse effects. The effects of nutrient timing for the recreational athlete are minimal. Unless you’re going to compete, you don’t need to worry about it. And you can always schedule your exercise on non-fast days.
- Breakfast is the most important meal of the day – It’s not. Studies show that eating breakfast does not help you lose weight nor does it prevent you from gaining weight.
- I’ll get hungry – When you first get started, you’re going to believe that. Once you get in the habit however you’ll learn that you were never really hungry in the first place. That urge to eat is usually the result of food cues that trigger your appetite, boredom, the desire to procrastinate, or actually, thirst and not hunger. I’ll discuss how you get over this feeling in my next post. But for now let’s look at the…
Health Benefits of Fasting
- Increases fat burning and weight loss – Your body has a hierarchy of energy sources. Through fasting your body consumes all of its preferred sources and starts working on fat. And since you’re consuming fewer calories, your body weight goes down.
- Clears your body of bad actors – Your body has a natural garbage collection process during which it removes damaged and potentially harmful cell detritus. As the flotsam and jetsam is removed, your mitochondria work more efficiently. Your mitochondria are what give you energy and are what rev up your metabolism. That is as science-y as I will get.
- Improved Insulin Efficiency and Lowers Blood Sugar – Your body learns to do more with less insulin which leads to lower overall blood sugar. The opposite situation (i.e. doing less with more and high blood sugar) is also known as Type 2 Diabetes.
- Decreases Inflammation – If you haven’t noticed, chronic inflammation is the new super villain in the health and nutrition world. It is a contributing factor to most lifestyle oriented diseases including cardiovascular disease, diabetes, and cancer. Our diets are a significant contributor. Intermittent fasting allows this inflammation to subside and not be chronic.
- Normalized hormone levels – All of those hormones you may have heard of (Growth Hormone, Cortisol) and lots you probably haven’t heard of (glucagon) that have either desirable or undesirable effects move in the right direction. And as stated in the myths sections, the hormones that you don’t want touched are not effected.
Lifestyle Benefits of Fasting
- It requires no change to your eating habits when you’re not fasting – Of course when you are eating there are always additional things you can do to improve your nutrition. Avoid trans-fats. Make plant-based foods a bigger part of your diet. You don’t need to do these things to achieve the health benefits above. If you add them to your repertoire, all the better. One thing I don’t suggest you do, except in special cases, is to add additional calorie restriction on eating days. Doing so will more than likely lead to the yo-yo weight situation we’re trying to avoid. It also will mess with the hormone balance I just promised would be unaffected. More on this in the next post on practical applications of the technique.
- It saves you lots of time – You will be amazed, on fast days how much more you can get done. I was shocked at how much of my day is spent in the act of selecting what I will eat, preparing it, consuming it, disposing of it, and traveling for it.
- It saves you money – If you’re fasting for 24 hours once or twice a week, you’re cutting your personal food bill by 14%-28%.
- You can use that saved money to do good – I set aside the money I save and donate it to a hunger based charity.
- It provides other opportunities for good – When you’re not consuming food, you’re lowering your global footprint. It is your small but worthwhile contribution to lowering demand for all of the energy and natural resources that go into producing and the disposal of your meals.
- It is the REAL Paleo Diet – Do you believe there are benefits to eating like our prehistoric ancestors? Those cavemen did a lot more hunting and gathering than actual eating. It was feast or famine for them. Our bodies are the evolutionary result of that. Fasting is a lot more legitimate way to promote a Paleo lifestyle than eating one of the new Paleo-compliant candy bars.
- Provides a unique opportunity to improve the mind-body connection – Many of the benefits people seek from activities such as meditation, yoga, or Tai Chi, for example, can be supplemented through a regular fasting routine. There is no better way to learn what the true sensation of “hunger” is. As stated in the myths section, most of the time when you think you’re hungry, this is not truly the case. My personal experience is that through intermittent fasting, I can better appreciate when I need to eat vs. when I want to eat. In addition, on fast days I often have a sense of serenity that is harder to achieve on eating days. I realize mind-body connection may not be a consideration for some people. If it is for you, consider intermittent fasting.
- It can be a spiritual experience or opportunity to further explore your spirituality – I know this is not a draw for everyone and while I consider myself a spiritual person, this is not a subject I’m an expert on. Spirituality is a very personal thing. But we all know that fasting is a ritual in many of the world’s religions. It serves many purposes in this realm (e.g. a means of atonement, a tool to develop discipline). You can Google fasting’s role in spiritual practice and learn more than I can ever do justice.
Given the above, you see that fasting is not just a fat-loss technique. It’s a life-long health and wellness technique.
If you would like any additional information on the science of fasting, Brad Pilon is your guy. While much of what I say above is the result of my own experience and research, no one knows more about this subject than Brad and he has said everything I said above before only more eloquently and with more data to back it up. I borrow liberally from his writing in the above.
My next and final post on this subject will discuss practical applications of intermittent fasting based my own personal experience and research.