Anabolic Power of Fasting

[Sabaki]

Over a decade ago, I was a big proponent of periodic fasting (or intermittent fasting, IF) as a method to achieve the longevity and health benefits of caloric restriction without the extremely adverse catabolic effects of continuous caloric reduction. This was long before IF became popular in the mainstream health community. Many members of DatBTrue’s forum experimented with IF and achieved impressive results, including some competitive BBers and professional athletes. Nowadays IF is touted by many doctors and health gurus as a cure for not only obesity and diabetes, but also for cancer, cardiovascular disease and neurological disorders like Alzheimers and Parkinsons. A youtube search produces hundreds of videos on the topic. Dr. Jason Fung has written several popular books on the subject. While many of Dr. Fung’s patients were diabetic or obese, he has also had great success with elite athletes, some with very low body fat. Alot more clinical and laboratory research has now been done providing a wealth of data about the physiological effects of IF. Naturally, such a radical idea has met with great resistance within the BB community. Still, some like, Dr. Jim Stoppani have had limited success promoting the IF approach within the BB community. All of the newly available data and individual case studies have been a total vindication of early proponents like DatBTrue.

One surprising thing we now know is that not only does IF have many remarkable health benefits, but it also has great anabolic power. It can be a powerful tool to not only eradicate stubborn fat, but also to boost anabolism and increase muscle growth. I intend to explain how IF does this, by discussing the specific mechanisms and pathways involved. I’ll try to separate fact from hype as well as offer practical advice for any who may be interested in trying IF, mistakes to avoid, etc. For now, I’ll just list the most important effects in no particular order. I’ll also reserve some space to come back and explain these effects in greater detail, in the future when I have more time.

But, first I have to dispel two big myths of IF: muscle wasting and “starvation mode”. Continuous caloric restriction causes both of these effects, but IF does not. “Starvation mode” refers to the fact that in times of food scarcity the body tries to conserve energy by reducing metabolism. “Muscle wasting” refers to the fact that in the absence of other energy sources the body catabolizes the protein in existing muscle tissue to provide the energy necessary for survival. When research first came out about the health benefits of caloric restriction in animal models, some people tried to replicate these effects by dramatically restricting their own caloric intake. These human subjects soon looked very much like Auschwitz survivors, skin and bones. Even if they live longer, I can not understand why anyone would want to do this to themselves. It is important to emphasize that IF produces neither of these effects. In fact, the surprising data is now very clear that IF actually increases muscle growth, while also boosting metabolism and energy utilization, enhancing athletic performance, both strength and endurance.

Here is the list, which I may modify in the future. If other members have experience with IF, please post your experiences. Also feel free to post questions, which I will try to respond to. Remember this is a preliminary, unsystematic list in no particular order.

Dramatic increase in insulin and leptin sensitivity.
Dramatic increase in natural GH production (and other growth factors, like BDNF, etc.).
Decreased ROS (Reactive Oxygen Species) production.
Increased Autophagy.
Nrf2 activation.
Increased mitochondrial biogenesis.
Reduction in chronic inflammation.
Activation of uncoupling proteins.
Improved immune system function.
Improved metabolic function including glycolysis, lipolysis and gluconeogenesis.
Ketone production.
Bolstering of natural circadian rhythms.
Stem cell activation and replenishment.
Increased catecholamine production.
Improved cognitive function, memory, focus, mental clarity, etc.
AMPK activation.
Sirtuin activation.

I believe these are some of the most important effects and mechanisms of IF.
There are, of course, many more. I’m also sure there are many other mechanisms and pathways that we still need to discover and learn more about.

[Sabaki]

Reserved Space

[Sabaki]

Another Reserved Space

[Sabaki]

One more reserved space.

[jrod]

How do you do it?

[Sabaki]

How do you do it?

The answer to this question depends upon your body composition and goals. The idea behind IF is that you alternate periods of fasting with periods of feeding. If your goal is to achieve the longevity and health benefits including cognitive improvement, extended fasting periods will produce the best results. You can start out with short fasting periods like 16 hrs, and build up to longer periods. During the fasting period, you should only consume water, electrolytes and vitamins. Avoid artificial sweeteners because even though they contain no sugar they tell the brain to produce insulin, etc. and are counterproductive. Data indicate that during the fasting periods your body will conserve muscle mass and during the feeding periods will produce more muscle mass, so even if your overall caloric intake remains constant your body composition will shift from fat to muscle.
If your are a lean, competitive athlete with very little body fat concerned about muscle loss, you should keep the fasting periods relatively short. It is also very important to break your fast with protein, not carbs, especially leucine and other BCAAs. Leucine activates the mTOR pathway which promotes myogenic hypertrophy and muscle growth. During the feeding period, the increase in growth factors, increased insulin sensitivity and increased activation of myogenic precursor cells (satellite cells), etc, etc. will all boost hypertrophy resulting in a long-term increase in permanent muscle mass.
How short is short? Most of us can fast for much longer periods than we realize. The record for fasting is 382 consecutive days with no caloric intake. Obviously, that guy had alot of excess energy stores. The current world champion lifter (in his weight class) eats only one meal per day and fasts 23 hours every single day. He deadlifts nearly 700 lbs, which is impressive for his size. (Of course, much bigger guys can lift over 1,000 pounds.) He is also a vegan and claims not to use any AAS. In this case, I believe him. (BTW, I don't promote veganism. Humans are biologically designed to consume meat.) But the fact that he can do this shows that many of our preconceptions about diet and nutrition are myths.
Here is a video. Also check out these videos. None of these videos existed a few years ago. I was writing articles about the benefits of IF and the myths of the need for constant feeding over a decade ago when nobody believed in IF. Not only were we right back then, but new experience and data show that IF is much more powerful than early proponents imagined.

[Dawgpound_Hank]

You apparently know a lot about it. Interesting topic. My Q would be if it is so good, why aren't more of the top guys (bodybuilding, powerlifting, strongman) using the approach. You mentioned a couple guys, but the Yate's, Coleman's, The Mountain's, Eddie Hall's, etc eat/ate in a more conventional fashion.

Regarding the guy who fasted for 382 days, IIRC he also was morbidly obese weighing around 1000 lbs, and was part of a medical experiment where they monitored him, but I digress.

[Darkness]

I think there’s a time and a place for it. I also think almost no women and few men are built for it. There are very specific hormonal responses that occur in a faster state and shit can get out of hand and snowball quickly and often. I’ve seen so many people literally ruin their physiques and metabolism at the same time not knowing what they are doing fasting. Everyone is different and one must know who they are.

And if you have any stress in your life that effects the cortisol/dhea balance do not even think of this fasting stuff. You will be skinny fat in weeks be crazy and be unhappy.