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 is 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 , som 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 1963 00:00:00,-01 --> 00:15:13,812 . So 1964 00:00:00,-01 --> 00:00:00,-01 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 is is 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 2478 00:00:00,-01 --> 00:18:24,762 . All 2479 00:00:00,-01 --> 00:00:00,-01 right . Thanks a lot .