Transcription
99 clinical trials, over 6,500 adults studied. Every fasting length head-to-head and fasting compared to calorie restriction. And one fasting style reigns supreme, and that is alternate day fasting. And in this video, I want to show you exactly why this is being considered the superior fast. I want to show you how you can actually do this fast. And the best part of this is I want to show you how we can do it together.
There has been so much research on fasting. So many of you have tried all the different fasts I've been recommending here on YouTube and in my books. And I'm really excited to bring you the research and the application of alternate day fasting because it's easier, it's more effective, and when we do it in community, it's a lot more fun. So, here we go. Let's dive in.
I think first we have to ask ourselves when we fast, why do longer fasts often get us a better result? And I think when I go to answer that question for myself, there is a unique experience the body goes through when it has been absent of food for a while. And one of those unique experiences is you hit an insulin floor. When insulin is in your system, fat burning shuts down. So the name of the game for weight loss is bring insulin down so it can hit the bottom floor and trigger that fat burning setting that so many of you are trying to reach. And when we look at, I've done a lot of videos here on the weight loss drugs. And when we look at actually the weight loss drugs, there is a part of the desire to eat less that is bringing that insulin floor down. But you can do it on your own without the help of the drugs. We just have to think about getting insulin down to its bare bottom so that your body starts to burn fat. Remember how I've explained over and over again, because I loved saying it this way, is that we have to look at health and our body as a chemistry experiment. So you are trying to change chemistry, and alternate day fasting has this incredible way to do that.
Now let's look at the science because there's a 2025 review. This is a very new review in the Current Nutritional Reports that said modified alternate day fasting was the most effective strategy across the board. And here's what they found. They found that people who performed alternate day fasting, they had an average weight loss of 11 pounds. That's 5 kilograms. They had an average of 3.5 centimeters come off their waist, and they saw a 7-point drop in their systolic blood pressure. Now I know many of you are going to ask me, well, what time period was that? And unfortunately, in this study, because it's a meta-analysis pulling together many studies, we have mixed time periods. But remember, the goal of this meta-analysis, this review, was to look at all these fasts head-to-head. So, we know it's superior for weight loss. We know it's superior for waist circumference and bringing waist circumference down. And we know it is superior for bringing systolic blood pressure down.
Now, a lot of you might think, well, maybe this won't work at my age. And I've been thinking a lot about this lately because there's so much discussion online about belly fat and specifically about belly fat for menopausal women. And in this discussion, what is emerging, and it really breaks my heart, is that like a woman, when she's after 40, can't lose menopausal belly fat because it's hormonal. And I just want to point out that there is a lot going on in fat accumulation. And what I'm going to show you as I break down alternate day fasting is that when we go longer periods of fasting, like the alternate day fasting guidelines, which is 24 hours of fasting, what we find is it's long enough to hit this insulin floor. Alternate day fasting isn't eating less every day. It's giving your insulin a true floor to hit every other day. So that your body starts to relearn this metabolic switch. That's the key to this whole alternate day fasting is we are training your body to learn the metabolic switch. How to be a great sugar burner and how to be a great fat burner. That's what makes this fast so superior is because it's training metabolic flexibility. If you are over 40 and you are a woman and you're looking for HRT to be able to get rid of the belly fat, in some cases it might work, and in many cases it won't, because it does not train metabolic flexibility. If you are on the weight loss drugs and you're trying to lose that midsection belly fat, again, the you're only metabolically flexible when you're on the drug. If you get off the drug, you're not metabolically flexible. So, this is why I love this style of fasting.
Now, let's dive into what the science is saying exactly and why alternate day fasting outperforms every other fast. I want you to think in these terms: Insulin up, fat burning down. So, if I want fat burning, I got to switch that. So, alternate day fasting was built to create a deeper experience. And because you're repeating it every other day, that's why you're going to end up getting the result you have been trying to get with your typical 16:8 fasting style. So, let's start there. They compared alternate day fasting to 16:8, which is probably the one you're doing. 16 hours of fasting, 8 hours of eating. And there was a 2025 review that said that time-restricted eating was actually the best for reducing fasting glucose. We love that. But it may not reduce, might not initiate fat burning. I want to repeat this: So when you eat a little bit every single day, you keep insulin high. When insulin stays high, fat burning goes down. When insulin doesn't come down enough, glucose is great. Glucose can come down, but we need insulin to come down. If insulin hasn't come down, then you don't go into that fat burning mode. We've got to be able to create that chemical reaction. And what alternate day fasting does and why it outbeats 16:8 is that it will allow the insulin floor to hit, increase the fat burning, but also, what they found in this 2025 review is that it brings down total cholesterol, it brings down triglycerides, it brings down non-HDL cholesterol, and it brings down systolic blood pressure. So the longer you go, glucose goes down and insulin goes down, and you're going to have a better reaction cardio-metabolically.
Okay, number two. This is another common one. We don't, we don't talk about this enough here on my channel, probably because I don't love this fast, and I love to bring you things that I like, like I do on myself, or I did, or I do with my patients, or I do with my Reset Academy members. But, um, it's 5:2. Five days of eating whatever you want, two days of not eating at all, so back to back. Now I have heard many people, including a lot of celebrities, are out on socials talking about 5:2 and how they've lost a tremendous amount of weight with it. But what this review is showing is that actually the problem is you're not training the metabolic switch. So alternate day, you eat, then you don't eat for one day, then you eat, then you don't eat for one day, and that starts to prime the metabolic switch, which increases your fat burning capabilities. Where when you're doing five days a week of eating and then two days of not eating, that rhythm doesn't tend to prime the metabolic flexibility switch that you are trying to get to be able to burn fat. Just like the 16:8, not long enough. Eight hours of eating might not be long enough to bring that insulin down, hit the floor, and start to initiate fat burning. You are a chemistry experiment. It's, it's really fun when you think about that because you don't need to white-knuckle it. You just need to know which strategy is best for you. Remember that frequency and the pattern of that frequency trains the metabolic switch, and 5:2 is not the normal pattern that will train the switch. Alternate day fasting will.
Okay. Number three, very common one that many of you do, which is OMAD. One meal a day. So what happens with one meal a day is that the insulin tends to get nudged up. It's very much like 16:8. And so a lot of times insulin can't come down enough. But when we go to eat one meal, we become chronically in a state of chronic under-eating. And so alternate day fasting is so much better because you have a full day of eating to get those nutrients in. Whereas with OMAD, you're trying to fit all those nutrients into one meal. This is phenomenal for those of you that have been asking questions about muscle preservation, which we're going to talk about here in a moment. Many of you have also been asking me about protein. How do I get all my protein in? Well, if you are noticing a difference with protein, alternate day fasting may be much easier for you. You get the benefits of fasting, plus on the days you're eating, you are able to eat enough protein to be able to build muscle if that's what you're noticing is helping for you. With OMAD, one of the considerations they have is that you're not getting enough protein. You're not getting enough nutrients in one meal a day. I think the same argument could be found with the 16:8 where you only have an eight-hour eating window. I also think this is one of the greatest challenges of our weight loss drugs because we can't get enough nutrients into our body when we're on these weight loss drugs if we're not really intentional about it. So, we're back at alternate day fasting. You're getting that day and you're getting the benefit and all the wonderful things that I'll tell you here in a moment that come with a 24-hour fast of not eating. And then you're getting, when you eat, you get to nourish yourself and all the things I've taught you here about GLP-1s and how do you go fiber, protein, fat, you can still do that style because you get a whole day to eat. Are you catching this? Like it's a really fun way to start to look at this. With OMAD, you don't hit that insulin floor. A lot of you, especially if you're diabetic, pre-diabetic, your hemoglobin A1C is really high, and you're eating one meal a day, it's not, it's just like 16:8. It's not enough to bring down glucose and insulin in order to put you into fat burning mode.
Okay. The fourth thing they looked at was alternate day fasting versus regular diets. And the punchline of the 99 trials was, and this is a big one because I hear this all the time, and I just want to, like, I'll put the links to the studies that I'm quoting here, that alternate day fasting was the only fasting method to beat standard calorie restriction outright. Okay, so this is really interesting. So, why does alternate day fasting work so well and can actually really outperform calorie restriction? So, when we go into calorie restriction, one of the challenges is we're hungry, right? Put in the comments if you were one of those people. We feel deprived, and we feel deprived every single day. I can tell you, I, when I was on Diary of the CEO the second time, Stephen asked me about calorie restriction, and I said, I don't know a woman on this planet who has succeeded at calorie restriction. It is hard to sustain. But with alternate day fasting, what we know is your mind is like, "Okay, tomorrow I don't eat. Today I do eat. And when I do eat, I can get all those nutrients in that I need to get in, my protein, my fiber. Okay, then tomorrow I don't eat." So there's a really beautiful rhythm here. Now, what we also know is that when you cut calories, you never trigger a cascade of hormones. That is really important. And when you go into this alternate day fasting, you do trigger these hormones. So, things like growth hormone. Growth hormone kicks in usually around 24 hours of fasting, and growth hormone slows down aging and it starts to tell your body to burn fat. You also, when you do this 24-hour fast on these alternate days, you also get a ketone burst. And I will continue to be the voice of every middle-aged woman needs a dose of ketones. And so ketones fire up the brain. They help with mental clarity. And you know what they do? They preserve muscle and they turn down hunger. So it's really interesting to me. Again, a lot of the criticism on fasting is this nutrient depletion. And when we look at through the lens of alternate day fasting, we go, "Wait, wait, we can get our nutrients in and we can make these hormonal changes." It's a really fun way to look at this.
So, what's actually happening in your body with alternate day fasting? And I want to take this hour by hour, and I want to look at three very specific mechanisms. And then I'm going to go into how you do it and how you can do it with us. So, one thing I want you to think about is we are eating one day, and then we are fasting, and then we're eating one day, and then we're fasting. So when you go 0 to 12 hours without food, this would be considered intermittent fasting. You burn through the food you eat and maybe some stored sugar from the last meal that you ate, and insulin starts to come down. When you go to 12 to 24 hours of fasting, your glycogen starts to run low. Glycogen is stored glucose, and insulin will hit the floor. So, this may, this explains to me why some of you can do a 15-hour fast, drop a lot of weight, and some of you do a 15-hour fast and you notice nothing. So, put in the comments if you fall into one of those camps. It's all based off of getting glucose and insulin down enough so that you can stimulate glycogen, which will speed up the fat burning. So, at 0 to 12 hours, you're just burning through the recent food. 12 to 24. Okay, now we're going to those stores, and insulin is coming down and hitting a floor. And when that insulin hits a floor, there are three, three hormonal changes that happen. One are ketones. Ketones are a signaling molecule. They calm inflammation. They steady energy. They quiet appetite. They signal to the brain we are in a food deficit state. Go ahead and turn on the other mechanisms in the body that keeps this brain sharp. Go ahead and turn on some of the cellular cleanup like autophagy so that we can clean out the cells that might end up becoming zombie cells that age you faster or cancer cells. And they also, like I said, go to preserve muscle because back in the primal days, if you had gone 12 to 24 hours without food, you needed to get up and move and go find food. So muscle preservation was really important. So the first thing you're getting in alternate day fasting that you may not get in all these other fasts are ketones.
Okay. Second thing is growth hormone. Let me know in the comments if you want to learn more about growth hormone because it's a really, growth hormone is a fascinating hormone, and I'd love to do more videos on it if you all are interested. A single 24-hour fast significantly raises growth hormone. A research study done years ago said that it's about a 1300% increase in growth hormone when you haven't eaten in 24 hours, and that is independent of weight loss. Growth hormone protects muscle. Growth hormone speeds up fat burning. Growth hormone slows down aging. So this alternate day fasting, we're getting more growth hormone.
Third mechanism that happens on this fasting day is autophagy. And this was based off a 2025 review in the Nutrients journal publication. And it said that an extended fasting window, like 24 hours, ramps up cellular cleaning and immune system renewal. So, when you are doing this every other day, what's happening is you're bringing inflammation down. You're cleaning up your body. You're getting those ketones to sharpen the brain. You're slowing aging down, and fat burning is increasing with the aid of growth hormone. So, you are retraining your metabolism. So this 2025 review, I'll put the link at the bottom, says that fasting this way is metabolic reprogramming, not calorie math. You are retraining your metabolism with this alternate day fasting.
Okay. So, have I got you interested? Let me know if you're going to fast with us. In fact, if you're going to fast with us, we are about to do Fast Training Week. Fast Training Week starts on July 6th, depending on when you're watching this video. And we have a whole guide, free guide that goes with it. Just put "companion guide" in the comments, and my team will send you a link, and everything that I'm stating in this video will map out how you can join us together and we can do this fast as a group.
If you are worried about going 24 hours without food, I want you to think about doing a modified calorie content on that day to start. I know I just said it's not the best for calorie counting, is not as good for weight loss and for waist circumference and for blood pressure, but I want to make sure that you're not white-knuckling your alternate day fasting experience. So, if that is you, what you're going to do is you're going to keep your calories under 500 calories. So, one day you will eat whatever you want. We'll talk about that in a moment. Next day, you're going to eat 500 calories of food, mostly protein and vegetables. I would stay off of carbs. And then the next day, you will eat whatever you want. So those are for people who are like really new to fasting and they're nervous about going 24 hours. If you are somebody who's fasted a while, then what you're literally doing is eating one day, not eating the other day, eating one day, not eating the other day, doing that for seven days. For Fast Training Week, we are doing it for five days. You can have, you can have coffee. Yay. You can have tea. You can have sparkling water. You can have Element tea, which we'll talk about here in a second. They have a new, they come in cans now, which is really cool. Um, so, but if you want to have that deep ketone, deep growth hormone, deep autophagy experience, then you're going to want to do this second level. This is the way I know alternate day fasting, but I know we have a lot of newbies here, and I want to make sure I gave you like an easier one to do to sort of warm yourself up. So, you would do on the fasting day, you would do 500 calories.
Now, on the eating days, what are we going to do? I'm a huge fan of what I call the Primal Menopausal Diet. I wrote about it in "Age Like a Girl." For those of you who have the book, it's on chapter, on page 106. And with the Primal Menopausal Diet, you are eating animal meats, if you eat that. You can do lean meats. You can do fish and seafood. You can do any kind of fruits and vegetables. We're not even looking at glycemic indexes here. Um, you can do nuts and seeds. And you can have, uh, a lot of roots and, uh, root tubers. And like I said, any vegetable you want. You can also have legumes. So, there's a lot there. I just don't want you eating breads, cakes, pastas, cookies. It's all in the companion guide. Just put "companion guide" and we'll send it to you. So, let's just go with the, I don't eat one day, and then I eat the Primal Menopausal Diet the next day. And so that you're getting, you're priming that switch going back and forth and back and forth.
For those of you who want to integrate this into your lifestyle routine, which I highly recommend, but you're new to this, I would recommend that you slowly ramp yourself up. So, week number one, you are going to do one day of 24-hour fast. Then week number two, you're going to do two days, but they're not consecutive. Remember, we already decided that doesn't work. And then week three, you're going to do three days of alternate day fasting. They're just not consecutive. So, and how long do you do this? Most research says 8 to 12 weeks of alternate day fasting can have a dramatic effect on your overall metabolic health.
Now, I want to talk to those of you that find fasting stops working because a lot of times when fasting stops working, it's because you do need to shake it up and you need to hit this insulin floor. So remember that if you are stuck, and this is a big one, those of you who are like, I've got stubborn belly fat, I'm having afternoon crashes, the food noise is going through the roof. I want you to use this alternate day fasting as a tool to unstick yourself.
Now, what about those of you who are like, well, I don't want to lose muscle? I think I've already addressed it, but I just, I get this so much. So, there was a 2024 random control trial in Frontiers in Nutrition that said, check this out, alternate day modified fasting in women decreased weight, decreased waist, decreased body fat, and had no significant loss to skeletal muscle or fat-free mass. And they claimed that it was because of the human growth hormone surge. When you get more growth hormone, it protects skeletal muscle.
Some of you are worried that when you go longer fasts like this 24-hour fast, that you can get brain fog. Well, there was a 2026 random control trial study in the Journal of Health Psychology that said, um, women who were new to fasting showed no drop in cognitive performance or mood. Go watch the video, the podcast interview I did with metabolic psychiatrist Georgia Ede, where she talks about especially women in middle age really need those ketones to sharpen their brain. Um, some of you are worried it's just going to feel awful, but most people who fail at fasts don't have a strategy. So, some of the strategy is that you need to be sure that you are taking more minerals. Another strategy might be that you need to lean into the Primal Menopausal Diet on the days off, so you're eating good quality food. I've really seen this over and over again where people who are eating poorly and then they do a fast one day, they really struggle. But when they're eating really well to stabilize their blood sugar, they actually will do incredibly well on the day off. My first exposure to alternate day fasting was a researcher who wrote a book years ago called "The Every Other Day Diet." She took a group of people over the course of a year. And what she found was that and had them do alternate day fasting and told them they could eat whatever they wanted on the days, like if they were eating fast food, eat fast food. Eat whatever you want on those days. I'm not recommending that. But if that was you, or or in this study, what they were saying is that by the end of the year, everybody's food preferences had changed. Their body weight had gone down, their waist circumference had gone down, blood pressure had gone down, cholesterol and triglycerides had gone down. Everything improved from this alternate day fasting. And that was like a 10-year-ago book and study. So, it feels awful. You have to remember that sometimes you need a strategy like adding in minerals. Sometimes you need a strategy like cleaning up your diet on the days you're eating so that the days you're not eating, you're making sure that your body is doing exactly what you want it to do.
Here are five steps that you can start to implement now if you want to alternate day fast. And then I want to go into how we can do it together as a community. So, I already said step one, you're going to make sure you start with one day a week. If you can go all 24 hours, that's great. What I used to do in my clinic all the time is I would say, "Okay, go, say, one day a week, go 17 hours." And then I would ask my patients, "How are you doing?" And if they were like, "Easy. Next week, okay, go 24 hours." If they said, "No, it's actually really hard," then what I would do is I would say, "Okay, how about we try 19 hours the next week?" So some of you might need to just start with one day a week and slowly over time stretch it to 24 hours. So it's really balls in your court. Other people just want to dive right in.
Step number two is you want to time your fast with your biology. So what this means is you want to make sure, um, that if you're, you want to fast like a girl. So don't do it the week before your period. Don't do it during ovulation if you still have a period. Um, also make sure that you have a free schedule. Start. If you're going to do every other day, make sure that you are not doing it on days that you have a lot of stress or you have a lot of social events.
Step number three is that you want to protect your minerals every single day. Element tea is a drink that was actually made for fasters originally. It has sodium, potassium, and magnesium in it. These are the key electrolytes or minerals that go down when you go into a fasted state. So, yes, you can drink this on the day off that you're not eating. You can have one of these. They come in packets. So, we'll put in the companion guide discount codes and how you get this stuff. Um, okay.
Step number four is that you've got to make sure when you're eating that you're eating good food. Otherwise, the day off is going to be bad. So, I've done a lot of videos on that here. And so, let's make sure that you don't go through the fast food drive-thru and that you're actually eating plenty of protein, uh, plenty of fiber, plenty of fat. Uh, we talked here, we've talked a lot about olive oil and how to make sure that you're getting enough omega-3s. So, all those principles still still are here for you. Okay.
Step number five, do it in community. I have a new phrase that I've been thinking a lot about is what we, we have a tendency to DIY our health. Do our health for ourselves. We just, oh, I can do this all on my own. I don't think health should be done on your own. It should be done together. I'd prefer that you did it. Do it together. And so, when you do it in community, what happens is you see what's possible, and you see other people that are like-minded that are trying to do it with you.
So, this is what we're going to do. Fast Training Week starts July 6th. And Monday, Wednesday, Friday of Fast Training Week, you will eat the Primal Menopausal Diet, and Tuesday and Thursday you will be your 24-hour fast days. Um, this would be an example of true alternate day fasting. Now, there is no fee for it. Like I said, just put "companion guide" in the comments, and you'll get the free guide, and we can do it here together on YouTube. You all can support each other. Go to the community page, um, and answer some of the questions and comments and posts we put there. If you're needing more help, you can also join my Reset Academy, which is a membership group where they are doing it together with a team of coaches. So, if you need that kind of support, just put "Reset Academy" in your comments, and my team will send you a link.
Again, I'm going to go back to this idea that whatever path you choose, community is key. And one thought I want to leave you on, which is that fasting still works despite the fact that there have been a lot of arrows pointed at fasting. Despite the fact that the media is not happy with fasting, despite the fact that influencers are getting paid by big pharma to support GLP-1 usage. So you try it. You tell me. You be the boss of your own health and see how this alternate day fasting works because I sit here 10 years later after giving thousands of videos to you all, and I can tell you that I am still a fan of fasting, and there are a lot of ways you can fast, and this one is one of the best ones. Put in the comments if you're joining me, and I can't wait for you to see how powerful you are and how you don't need to spend thousands of dollars to lose weight. You are stronger than that. You have come with a lot of bells and whistles in your body. You just need to know how to use those bells and whistles. So, looking forward to doing this fast with you. And as always, I hope that helps. If you like this video, you're definitely gonna want to check out the next.