 Hey, everybody. Dr. O here. So, kind of a different topic here. We've been talking about calorie cycling and how powerful of a tool it is, but one of the reasons that I do think that it's especially valuable is that calorie cycling can slow what's known as metabolic adaptation, or maybe you've heard this called survival mode. When you go into too strict of a diet, your metabolism tanks, you know, your libido drops, you get really tired, all these things happen in response because your body is trying to survive, right? That's what's known as metabolic adaptation. When you lose weight, your metabolism will adapt to try to keep you from losing more weight, right? This is a very common thing, right? So you are here. You're sitting here because your ancestors had thrifty metabolisms, which meant that they could survive in a world where there was famines and there was food shortage, but you're sitting here now wondering why you have such a thrifty metabolism, which is making it really hard to survive in a world of excess. So having a thrifty metabolism or metabolic adaptation responding to times when there's not food by adjusting the metabolic rate and adjusting things like physical activity makes perfect sense, but we just have to, we have to figure out ways to minimize this. We cannot eliminate it, and I think that calorie cycling is a great way to minimize it. I like to say I was really good at starting diets. I've lost, I've lost 40 or 50 pounds several times, right? The beginning of diets was always easy, but then when the going gets tough, when things like metabolic adaptation start to occur, then I gave up and I fell off the wagon and I had to start over again and again and again. This is the first time that I've used fasting and calorie cycling, and it's also the first time that I've been able to have long-term success. The enemy of every diet or is this, is this metabolic adaptation. So think about it. You go on a diet where you used to eat 2,500 calories a day, and then now you're eating 2,000 calories a day. And for a while you lose a pound a week, but then all of a sudden you're still only eating 2,000 calories, but now you're losing half a pound a week and then a quarter of a pound a week, and then you're not losing weight. That's what I mean when I talk about metabolic adaptation. Now some of it is completely makes sense, right? You're going to be carrying less of you around. You've lost weight, so your metabolic rate is generally going to drop. The only way to keep that from happening during a weight loss effort is to also build your metabolism by building muscle, if we're talking about basal metabolic rate. And I've talked about that in other places here, where my metabolic rate has actually gone up 181 calories a day while I lost 165 pounds. And that's because I added 15 pounds of lean mass during the process. But if you don't do that, your metabolic rate is going to drop. There's less of you to keep around. And we'll talk about other ways to boost your metabolism in different places. We're just talking about this kind of survival mode mechanism here. So when you fight your body, it has no other option, no choice but to fight back. If you scare your metabolism, if you scare your body, then it's going to adapt. So we need to find ways to let our body know that the weight loss we're going through is safe and is acceptable. Because if we scare our metabolism, then it will fight back. It will, yes, your metabolic rate will go down, but you'll also have, there'll be subconscious triggers to eat more food, subconscious triggers to move less. These are all part of the metabolic adaptation process. So your subconscious mind doesn't understand that you're on a diet. It just knows that you're not getting enough food. Your subconscious mind thinks that you're in the middle of a famine, and it's trying to save your life by holding on to all the body fat you have. So your conscious mind understands that you're within a mile of a million calories, but your subconscious mind won't. You can't explain that to your lizard brain, so to speak. So what does this have to do with calorie cycling? We have to figure out how can we be as aggressive as possible with our weight loss without scaring your metabolism. And this is why I like alternate day fasting. I change the equation drastically one day, right? I eat nothing. And my body's like, oh man, this is not good. There's no food around. But then you change it back real quickly. Instead of just being in a calorie deficit every single day and having your body slowly adapt and having weight loss slow and slow and slow, I eat nothing. And being a huge calorie deficit, my body starts to get concerned, but the next day, not only am I eating at maintenance, I'm overshooting. I recommend consuming 25% to 30% more than your maintenance calories on your eating days if you're doing alternate day fasting. So your body's like, whew, it's OK. There's no time for these survival mechanisms to kick in. There's no time for your metabolism to adapt. And then all of a sudden, boom, I'm fasting again. Then I'm eating again, fasting again. There's no other way for me to explain how I've had such amazing success, 165 pounds of weight loss in a year compared to all the other weight loss attempts that I've had in my life. There was a time when I was younger that I was eating 1,000 calories a day, and I was doing three hours of cardio a day. And I could not lose weight and keep it off as well as I can now. There's no other way for me to explain how basically a 1,700 to 2,000 calorie average has led to such amazing weight loss and sustainability compared to times that I've been more aggressive. The difference is I'm really aggressive on my diet one day, and the next day I'm actually overfeeding a bit. So let's go ahead and look at the science behind this. Alternate day fasting for weight loss in normal weight and overweight subjects, a randomized controlled trial. This was a 12-week study where the people that were doing alternate day fasting actually lost eight pounds in 12 weeks, and their fat-free mass did not change compared to the controls. So they were able to hold onto their fat-free mass and only lose fat, which is our goal. You don't want your body or your metabolism adapting. Next, intermittent energy restriction attenuates the loss of fat-free mass in resistance-trained individuals, a randomized controlled trial. So in this study, a two-day refeeds, basically two-day refeeds with lots of carbohydrates preserved fat-free mass and metabolic rate compared to people that were on a continuous calorie restriction diet, and they were also resistance-trained. So the nice thing about this is basically you can lose fat without your metabolism dropping if you have periods where you have low calories and periods where you have high calories. Now, this is not exactly what I'm recommending because I don't recommend two-day carb refeeds, but the point is the same. You lose fat one day, then you tell your metabolism, it's safe the next day, and then you repeat. So why? Why does this actually work? Well, let's look at this study. The response of leptin to short-term and prolonged overfeeding in humans. So as you lose weight, your leptin levels are gonna drop. Leptin is basically a fuel gauge. Your fat produces leptin and tells your brain how much fat that you have on your body. So if you're losing fat, then you're gonna be producing less leptin. Every dieter in the world has had their leptin levels drop while dieting because their body fat's going away. And your body uses that as a signal that we're in the middle of a famine, you're losing fat, we should stop moving and we should start eating. But short-term overfeeding is associated with a moderate elevation of circulating leptin levels. So instead of leptin just slowly, steadily plummeting while you're on a diet, it goes down, up, down, up because of these, the overfeeding. So your metabolism gets really scared one day and then boom, the next day. Oh, I feel much better. I ate more than enough because of overfeeding. In this study, the overfeeding was a 40% in calories above maintenance. I recommend 25 or 30, but same principle applies. So your metabolism gets scared for one day, next day feels great. It didn't need to do all the metabolic adaptation like dropping thyroid hormone, et cetera. So studies have repeatedly shown that refeeds in diet breaks can help minimize metabolic adaptation. I'm not saying they're necessary, but basically what we're doing here is we are fasting one day to lose fat. The next day, we're overfeeding to boost leptin levels and we do it over and over again. We can't eliminate the problem. Your leptin levels are still gonna go down, but we're mitigating some of the metabolic adaptation damage. So it isn't magic, I want you to understand that. Another study, leptin responses to overfeeding, relationships with body fat and non-exercise activity thermogenesis. This study showed the same thing that with overfeeding, about 30 to 40% increase in calories above maintenance, leptin levels went up. So your leptin levels are gonna be spiking every other day if you're using alternate day fasting. And then this study also showed though that while you're eating more, you should be increasing your physical activity, your non-exercise activity thermogenesis. So this is why I recommend that your eating days should be the days that you're exercising and the days that you're most physically active if you wanna minimize the fat gain that would come with this overfeeding. We don't just overfeed to overfeed, we overfeed to fuel our physically active bodies. All right, this one here, the effects of short-term carbohydrate or fat overfeeding on energy expenditure and plasma leptin concentrations in healthy female subjects. This one found that carbohydrate overfeeding increased leptin concentrations by 28% and increased 24-hour energy expenditure by 7%. So those are all great. But so yes, if you do wanna boost your leptin levels as much as possible, you would want to have extra carbohydrates on your overfeeding days. But if you're doing a low carb diet, if you've got a ton of body fat to lose, that may not be your priority yet. So don't worry about that. But I just wanted to show you that this isn't magic, right? My leptin levels have dropped because I've lost 165 pounds. But I feel like this calorie cycling strategy has kinda softened the blow and minimized the damage. My metabolic rate has gone up while losing 165 pounds. I can't explain it in any other way, but the power of fasting. All right, I hope that this has helped you. Have a wonderful day. Be blessed.