Siim Land has written an excellent book called “Metabolic Autophagy: Practice Intermittent Fasting and Resistance Training to Build Muscle and Promote Longevity.” Here, we discuss Land’s latest book, “Stronger by Stress: Adapt to Beneficial Stressors to Improve Your Health and Strengthen the Body,” which came out in July 2020. It reviews the really important concepts of hormesis and antifragility.
Stronger by Stress
As it pertains to COVID-19, evidence suggests if you can get two key variables right — a vitamin D level of at least 30 ng/mL (75 nmol/L) and metabolic flexibility — your chances of getting sick from SARS-CoV-2 infection are fairly remote. But improving your resilience against stress is also important. “If your body is unfit or lacking key nutrients, then even the smaller stressors in your life are going to become more dreadful. You’re going to experience chronic stress, and you’re going to overactivate the sympathetic nervous system, even if you’re stuck in traffic or if you spill a cup of coffee or whatever it is.These small stressors can become really massive if your body is incapable of dealing with those stressors. On the other hand, if your body has been exposed to the right amount of stress at the right time, then it has also built up this higher level of stress adaptation and resilience. So, the small stressors are becoming literally meaningless. You have a bigger capacity to face even the larger stressors.”
What Is Antifragility?
Antifragility is a term coined by economist Nassim Nicholas Taleb in his book, “Antifragile: Things That Gain From Disorder.” The term describes a state that is the opposite of fragility. Antifragility describes how stress makes you stronger rather than breaking you down or apart.
“[Antifragility] isn’t precisely the same thing as robustness or resilience,” Land says. “Something that is robust is something like a piece of stone or a metal. You can heat it, you can drop it on the ground. It’s not going to break, but it’s going to stay the same, it’s not going to change, whereas something that is antifragile is going to gain from the stress.”
Time-Restricted Eating Builds Antifragility
One of Land’s favorite tools for health and longevity is intermittent fasting, or more accurately termed, time-restricted eating, and one of the reasons for this is because it allows you to become metabolically flexible and insulin sensitive, which builds your antifragility.
“A [2019] study in the New England Journal of Medicine found intermittent fasting mimics a lot of the same effects of calorie restriction. It can actually be somewhat more beneficial because it not only has life extension benefits, but it also turns on certain key defensive mechanisms inside a body that make it more antifragile and also provide additional health benefits. One of those things has to do with autophagy, but there’s also things like increased glutathione, increased NRF2, sirtuins and NAD and many other longevity-boosting and immune-strengthening pathways that get activated when you’re fasting that don’t necessarily get activated when you are restricting calories.” So, time-restricted eating is a great way to get the benefits of calorie restriction without experiencing the negative side effects from it, because extreme and prolonged calorie restriction can also leave you vulnerable and more fragile by triggering muscle loss, for example. That will actually shorten your life span and make you more vulnerable to potential dangers in your environment, such as falling and breaking your hip. Intermittent fasting can sidestep these negative side effects.
Time-Restricted Eating for Muscle Building
A persistent question surrounding
intermittent fasting is what the best strategy is. Should you eat just once a day, or can you get away with two or more meals as long as you eat it all within a certain time window? And, if so, how long can that window be?
Land comments:
“I think there isn’t inherently much difference between eating one meal a day or doing the 16-to-8 type of intermittent fasting where you eat twice a day within eight hours because, already, if you’re fasting within one 24-hour period, then the fast itself isn’t substantially different. The amount of autophagy wouldn’t matter that much either in such a short timeframe, as long as you’re still healthy.”
Now, if your intention is to build muscle, having two meals a day within a six- to eight-hour window would make more sense. Having just one meal a day is likely better if you are seeking to lose weight, but might be challenging. This is likely for the simple reason that you’re only going to build muscle when you activate mTOR, and to activate mTOR you need to introduce protein and leucine or branched-chain amino acids, along with some healthy carbohydrates. If you eat twice, six hours apart, you can activate mTOR twice a day, thus allowing you to get better muscle-building benefits. As explained by Land:
“What determines your muscle growth throughout the 24-hour period is the balance between mTOR stimulation and autophagy. So, if you’re eating only once a day, then the amount of mTOR stimulation is relatively small compared to eating twice a day or three times a day. That’s why if someone has the goal of increasing their muscle mass, maintaining muscle mass or preventing sarcopenia, then for them it is much wiser to incorporate more frequent meals. For them I would say that a 16-to-8 type of fasting where they eat twice a day is perfectly suitable, and is actually better than the one meal a day.
It becomes increasingly more difficult to maintain muscle mass if you’re already predisposed to sarcopenia and you’re eating once a day, because there’s a threshold of how much mTOR you can stimulate per meal, and how much muscle protein synthesis you can create per meal as well. It doesn’t have to mean that you start eating six times a day. Increasing the eating window is generally a better idea.
For most people, I would say that the 16-to-8 type of fasting, where they fast for 16 hours and eat within eight hours, is a really good balance between getting a daily stimulation in autophagy, while at the same time also stimulating enough mTOR and being able to build muscle.”
In the context of stress adaptation and antifragility, if your body becomes too accustomed to the fasting because you’re eating only one meal a day all the time, then that can eventually slow down your metabolism and lower thyroid functioning. This in turn makes you more prone to insulin resistance, which is exactly what you’re trying to avoid by eating just once a day.