Mind Body Evolution Podcast

Intermittent Fasting

Today Dr. Josh Stout discusses intermittent fasting to promote health and reduce metabolic disease including hypoglycemia, type 2 diabetes, high triglycerides and high blood pressure.

Dr. Josh Stout, PhD

Nov 10, 2023 — 13 min read

Please scroll down for links below the transcript. This is lightly edited AI generated transcript and there may be errors.

Dr. Josh Stout 0:07

This is Dr. Stout again. I'd like to do a short technical addition. I've been talking a lot about the mind part of mind body evolution, and I think people might be interested in just learning a couple of things based on sort of evolutionary knowledge of what's optimal for the body. So I'm going to talk about intermittent fasting today. Intermittent fasting is popular and pretty much follows what humans would have evolved for, right? They would have had regular food and then they would have had intermittent periods where there was no food as they had to go get some. And so it's matching of fairly closely what we were evolved for. But what does it actually do for us? How does it work? What are its benefits and what are its drawbacks? So does it even have an effect on weight loss

So early? As early as 1988, human growth hormone was found to be four times higher after fasting after 24 hours of fasting and remained the same for five days. Now, human growth hormone is essentially the opposite of insulin in many ways. So whatever insulin does, human growth hormone does the opposite. So human growth hormone will reduce glucose uptake by muscles, increase glycogen output from the liver producing glucose. So the glucose in the in the blood increases and it decreases glucose oxidation. So overall, it's going to increase the amount of glucose in the blood, which would make it really, really bad if you're diabetic, for example. So it's not something you want to do if you need to have a controlled blood glucose. So this is going to increase blood glucose, particularly after you you are fasting, right? When you're fasting, it makes sense to try and keep your blood blood glucose high, but it's going to remain high for days afterwards due to the higher human growth hormone. But higher human growth hormone does have some benefits, right? This is a steroid that people can abuse to increase muscle mass, but it will also do the same thing after fasting. So fasting can help increase the ability to develop muscle while exercising. So if you fast followed by a light meal, then exercising will have additional benefits beyond what it would normally have.

While it's terrible idea to do intermittent fasting, if you are a diabetic, it will help prevent type two diabetes because it will increase insulin sensitivity. So in type two, diabetes is defined as a decrease in insulin sensitivity, you need more insulin to have the same effect on glucose and after fasting the insulin will have a greater effect on glucose. So it actually is is able to work more effectively. So even though human growth hormone is countering the insulin, you're also becoming more sensitive to the insulin because the insulin is being countered, your body needs less to have the same effect because your body is going to be pushing against what's countering it, right. So if you have too much insulin, your body starts to not notice insulin, it becomes less sensitive. That's when you eat too much sugar, you have too much insulin and you get type two diabetes. If you have too little insulin because European fasting, you haven't gotten any sugar and you have high growth hormone, high human growth hormone as a sort of counter raising glucose, then your body's going to start becoming more sensitive to insulin. And so you can have the opposite of type two diabetes. So it is somewhat paradoxically really good for you to have a increased sensitivity to insulin.

So if you have glucose just before exercising, you end up with a short term increase in human growth hormone and a significantly slower oxidation of fat. So that is that is I would not say is a is a good way to go. But human growth hormone in general due to fasting will encourage the burning of fat. So again, it's almost the opposite of insulin. Insulin is the steroid that creates fat because you deposit fat. So fasting by releasing human growth hormone is going to release the fat.

The idea of a starchy meal making you feel more tired is probably also related to the relationships between human growth hormone and insulin causes a spike in insulin. And this is going to block fat utilization. So remember, insulin is the opposite of human growth hormone. If you increase insulin, insulin wants to make fat, then you're not going to burn fat. And so you you end up with high insulin, but you also have high blood sugar. So this can end up signaling feelings of tiredness, whereas intermittent fasting can produce sort of the opposite effects where you can certainly being hungry can make you tired, but if you can not be tired response to be hungry, it will make you perhaps feel more up, more alert. In healthy non obese men. Intermittent fasting showed no loss in body weight, no loss of activity and no lowering of heart rate, so there was no direct metabolic effect other than the increased insulin production sensitivity, sorry, increased insulin sensitivity and increased human growth hormone production. So there was no change in the overall body weight. So what with less insulin, it was much more easy to burn fat. And those that fat was being used to maintain glucose levels during the entire time. One of the downsides, though, is with a huge increased human growth hormone, you're blocking uptake of the glucose by muscles. You're not blocking it, but you're slowing it down. So the muscles themselves lose a little bit of strength and you become more efficient. And if you want to lose weight, becoming more efficient isn't necessarily something you should be striving for. So you're actually going to be burning sugar more slowly due to fasting, no significant drop or rise in basal metabolic rate. So while the muscles are slowing down uptake, you're not actually lowering your overall use of use of glucose and you can maintain glycogen and even even sometimes with with exercise. One of the studies was showing that our bodies are able to maintain homeostasis by providing extra extra glucose. And this is, you know, coming coming from liver and you can just provide during exercise and then what happens, the fat begins to begins to become burning. And so the fat produced and released after human growth hormone is is produced from fasting, is able to maintain the overall blood glucose in rats. When rats are given intermittent fasting, the response to insulin increased sevenfold. So a tremendous increase in sensitivity to insulin and in obese individuals. Fasting does show an increase in appetite, as you might expect. Right? They're hungry, they haven't eaten, but a somewhat of a reduction in metabolic rate and a an interest in exercise, which is interesting. I would not have expected that necessarily. But it, I suppose, is evolutionary based. If you're if you're hungry, you might want to go out and find some food.

HGH, insulin like growth factor goes down during fasting. So again, human growth hormone goes up. Insulin like growth factors go down. And then after you're done fasting, they return to the regular levels, but it is slightly lower levels. So again, it increases sensitivity to insulin and to insulin like hormones.

HGH is associated with muscle development. So both HGH and HGH can develop muscles, but HGH is specifically connected to aging. And I there is a possibility that by fasting regularly, you might be ever so incrementally reducing some of the effects of aging. So there isn't a direct effect on body weight or body fat. Your metabolism stays about the same, maybe a little bit slower with with the reduction in uptake of glucose from the muscles. But in general, your metabolism doesn't doesn't change radically. Human growth hormone goes up, b glucose remains about the same, and energy levels stay roughly the same because you're maintaining that blood glucose. I certainly when I intermittent fast have to be careful of that. If I go too long or in a way that reduces my blood glucose, I could get a headache or I could get fatigue. And I find moving around really helps. So I get up and go take a walk or I go teach and I do things that allow me to be active. And somehow that seems to balance the the blood glucose in a much better way. And I avoid getting a headache and I avoid getting sleepy.

I would definitely say that intermittent fasting would exacerbate diabetes and short term, but overall would increase sensitivity to insulin. So anything that's increasing sensitivity to insulin is excellent.

Insulin like growth hormone goes down during fasting, which again might have anti-aging benefits.

There's a reduction in hypoglycemia, less danger of type two diabetes. And so these are all related due to what is known as metabolic syndrome. So all of the things that are related to having a high insulin level, like high blood pressure, high blood pressure, high triglycerides, high cholesterol, all of these things are going to be reduced through intermittent fasting, eve though you're not really lowering your overall body fat because your body's going to maintain homeostasis, you're going to train, your body is going to try and make itself stay the same weight. So with a D, a fat makes leptin, leptin is is what tells you to tells you to be hungry. And so when you're when you're fasting, there's a decrease in in leptin and you're going to end up eating just as many calories on your non fasting days. So the only way you could actually lose weight through intermittent fasting is if you also had calorie restriction on regular days. And now you're starting to get closer to, let's say, an eating disorder. If you're if you're constantly trying to restrict your calories, that could actually be dangerous. So that would be something to be careful of. Maintaining homeostasis is really the goal you want to look for while increasing health, you know, exercise. And this is, you know, some sort of dietary control. I just find intermittent fasting to be easier than other kinds of dietary control. I want to be able to eat what I want most of the time and then a couple of days a week I do intermittent fasting, so lower triglycerides, lower blood pressures are certainly possibilities that have to be longer term studies to really find out there's some some indication there might even be a anti-cancer benefit.

Again, overall reduction in metabolic disease, there's not clear if there's differences between periods of time for fasting, but it seems as though the minimum is about 15 hours to really get the the glycogen stores out of your liver and to have a drawdown in glycogen so you can actually start burning fat. But the effect seems the same in most of the short term studies that have been done. It'll be interesting to see longer term studies. So it seems as though we've evolved to resist the bad effects of fasting, right. So what are the bad effects of fasting running out of fat? Now we might think that would be a good thing, but we would definitely want to maintain fat as you know, to maintain our ability to to be fertile and particularly for women are going to have a very strong incentive to maintain fat.

Fasting doesn't stop activity and actually seem to encourage activity in some people. I certainly feel it that way myself sometimes. So this is exactly what we're evolved for. Fasting is designed to get you out there, maintain as much body fat between fasts as possible, build up that body fat so that when you're when you're needing it, you can burn it and turn it into glucose, maintain your metabolism and maintain your energy levels so that you can go get that food. So it is very effective at burning the fat, but the fat will be put right back again and there is a compensatory health benefit of of the increasing insulin sensitivity which is going to then have the negative side of if you have increased insulin, you're going to try and not burn fat. So this is what's going to happen as soon as you're eating again is your body's going to try and store that fat. Even even better by having a more sensitivity to the insulin it stores the fat. I it seems as though frequency of meals is what you really want to avoid, particularly frequency of carbohydrates. Frequent carbohydrate meals are going to be constantly giving you an influx of of blood sugar and your insulin is going to be constantly rising. And so you're going to be constantly putting on fat and having the problem of decreased in insulin sensitivity are going to be moving towards hypoglycemia. You're going to be moving towards all the metabolic diseases. So intermittent fasting fights this as when when you are hungry for a long period of time, the glucose which is stored as glycogen in your liver, is released from your liver and but you only have a few hours of this. So if you do it as you're, as you're sleeping and then into the morning, you burn through your glycogen reserves and then you start really burning fat. And this is this is, you know, very good for you for a number in a number of ways. And it's the belly fat that gets preferentially burned. So if you can maintain low insulin levels when you're not fat, fasting by avoiding sugars, eating normal foods, but trying to avoid those spikes of insulin and sugars, you'll actually maintain a much more healthy relationship with your own fat as you fast your you'll you'll burn belly fat. And then when you store fat, it's much less likely to be belly fat. If your insulin is low. Insulin tells the fat to go directly to to to to belly fat. And so if you can keep that insulin low, even if you're storing fat and you maintain your overall fat levels, your fat will start to redistribute from belly to of other portions of your body. And in my opinion, this has an aesthetic value. That's just my own opinion. But I seem to like a redistribution of fat rather than it all being concentrated in the belly. All right. I just wanted this to be relatively short and sweet, so I'll stop it there and I will continue on with some more technical notes next time. All right. Thanks a lot.

Sample Intermittent Fasting Program

Designing a daily health program that combines intermittent fasting and exercise can be an effective way to improve your overall well-being and fitness. However, it's important to consult with a healthcare professional or a registered dietitian before starting any new diet or exercise routine, especially if you have underlying health conditions.

Here's a sample daily health program that incorporates intermittent fasting and exercise:

Time-Restricted Eating (Intermittent Fasting):

Intermittent fasting (IF) involves cycling between periods of eating and fasting. The goal is to extend the fasting window and restrict calorie intake during certain hours of the day. There are various methods of IF, but one common approach is the 16/8 method, where you fast for 16 hours and have an 8-hour eating window. Here's a sample schedule:

Morning (Fasting Period):
- Wake up and hydrate with water, herbal tea, or black coffee (no added sugar or cream).
- Engage in light activities like stretching or yoga during this fasting period.
Mid-Morning (Fasting Period):
- Continue to stay hydrated.
- You can also include a short, low-intensity walk or gentle exercise.
Early Afternoon (Breaking the Fast):
- Start your eating window with a balanced meal that includes lean protein, healthy fats, and a variety of vegetables.
- Consume a portion of complex carbohydrates (e.g., whole grains, sweet potatoes) to provide energy for your upcoming workout.

Exercise Routine:

Incorporate exercise into your daily routine to enhance your fitness and overall health. Aim for at least 30 minutes of moderate to vigorous exercise most days of the week. Here's a sample exercise plan:

Late Afternoon (Post-Meal Exercise):
- After your early afternoon meal, allow some time for digestion (approximately 30-60 minutes).
- Engage in a workout session, which can include activities like strength training, cardio, HIIT, yoga, or a combination of these.
- Focus on different muscle groups and exercise types throughout the week for a balanced routine.
- Stay hydrated during your workout.
Evening (Post-Exercise):
- After your workout, have a post-workout snack or meal rich in protein and carbohydrates to aid recovery.
- Include lean protein sources like chicken, fish, or tofu, and complex carbohydrates like brown rice or quinoa.
- Continue drinking water to stay hydrated.
Evening (Closing the Eating Window):
- As your eating window is closing, consume a light, nutrient-dense meal or snack.
- Avoid heavy, calorie-dense foods close to bedtime.
- Hydrate with water or herbal tea.
Bedtime:
- Aim for a consistent sleep schedule and get 7-8 hours of quality sleep to support recovery and overall health.

Remember that individual needs vary, so adjust the timing and content of your meals and workouts to suit your lifestyle and preferences. Listen to your body, and if you experience any discomfort or adverse effects, consult with a healthcare professional or registered dietitian for personalized guidance. Additionally, keep track of your progress and make necessary adjustments as needed to achieve your health and fitness goals.