How many times have you heard that a certain diet is going to be the best way to lose weight? If you spend any time on social media at all, you've probably even heard about the latest fad. Here is the only weight loss technique that actually works. It's intermittent fasting.

Intuitive eating example.

Check this out in case you're sick of dieting, but you'd like to get you to stay at your happy weight.

Ladies, if you are serious about losing body fat, here's why protein is going to be your BFF.

If you follow a ketogenic diet, you will lose weight very fast. This is nothing new. Dieting fads or tricks have been around for centuries. In the 20 years that I've been a health journalist, I've heard about so many different types of diets. It's amazing. All of them claim to be the next big thing. But I think in recent years, even more Americans than ever are trying dieting. Perhaps that's no surprise. After all, obesity rates continue to rise. But that is also the issue, right? Obesity rates are rising despite more people dieting. At the same time, most people realize that dieting rarely leads to long-term weight loss. It is a vicious cycle. One study shows that as many as 80% of people who lost weight through dieting and exercise, regain most of that weight back. Then there is the yo-yo nature of all this, which can make subsequent attempts to lose weight even more challenging. Then what is the solution?

The US population would do best getting rid of the crappy carbs and adding healthier fiber-containing carbs and healthier unsaturated fats.

Christopher Garner is a Stanford University professor. He has spent decades studying nutrition and all the different ways that people eat. If you Google this topic, his name is sure to pop up because he is a superstar in this health space. Now, the message you just heard from Professor Garner may sound pretty simple. It may sound like something you've heard before, but here's the issue. Most people still don't do it for all sorts of different reasons. And to be fair, I know that actually eating a diet that prioritizes wholefoods and fruits and vegetables is sometimes easier said than done. But here's the thing that really made me want to speak to the professor. His research shows that two people following the same exact healthy diet can have wildly different results.

Somebody 15 pounds and somebody lost 50 pounds and everything in between. Wow.

Now, why would that be? If eating a healthy diet isn't enough for everyone, where does that leave us? In order to answer that question, Today, we're going back to the basics. I'm Dr. Sanjay Gupta, CNN's Chief Medical Correspondent, and this is Chasing Life. There's this gold golden rule in the dieting world that the solution to losing weight is to burn more calories than you eat. It's simple. Calories in, calories out. So I decided to start there by asking Professor Garner if a calorie deficit was in fact necessary to lose weight.

It is not the only thing, but it is the main thing. And it's mostly diet, not exercise, because exercising makes you hunger and you eat more calories. So there's a really nice summary, Sanjay, in 2013, that was a combination of the American Heart Association, the American College of Cardiology, and the Obesity Society. And they had summarized all the evidence for diets, and they had 20 different diets, and they had all the papers on them. It was very methodical. They said there's more evidence for some than others. Some of the studies are higher quality than others. At the end of the day, they said, Bottom line is on every one of these diets, people lose weight when there's a calorie deficit. That was one of the main conclusions reasons, and it was as simple as that.

All right, so counting calories is the main thing, as he said. But it's not the only thing. There is more to this story.

Okay, Sanjay, we have done a mathematical formula, and based on your age and weight and physical activity level and gender, you probably need this number of calories a day to maintain your weight. And I'm going to say it's 2,800 just for the sake of argument. And so to lose weight, you need be in a calorie deficit. So we're putting you in this program. And if you want to lose a pound a week, it's going to have to be a 500 calorie deficit per day. If you want to lose two pounds a week, it's a thousand calorie deficit. And your immediate reaction should be, holy crap, you want me to eat every single day, 500 calories or a thousand calories less. I'm going to be hungry all the time. This sounds miserable, right? So psychologically, you're You're not setting yourself up for success very well there.

Losing the first pound. That's easier than losing the second pound, which is easier than losing the third pound, and so on.

So let's say you wanted to lose 20 pounds and you managed to If you had a 3,500 calorie deficit, you would probably lose a pound. And maybe the second pound would come off with a 3,500 calorie deficit. But the further you go, it has to be a bigger and bigger and bigger deficit. And that's why... Because people's bodies react to that and they become more metabolically efficient. And so the same calorie deficit won't do it for you. That's why people's weight loss starts to plateau. You can't just disappear. You can't just have a 3,500 calorie deficit and all of a sudden be gone. So the longer you do this and the more weight you lose, the more discouraging it becomes because it actually takes more effort to lose the next pound, which is psychologically demoralizing for some people.

This means if you're following the same diet over time, it will actually be harder for you to lose weight. Our bodies are going to fight us every step of the way. You see, your body wants to hang on to weight. It's part of survival. And here's where it gets even more interesting. Professor Garner's research suggests that even when different individuals follow the same diet, the results can really, really vary.

It's called Diet FIT. Let me see if I can remember the acronym. Diet intervention examining the Factors Interacting with treatment success. And so this had been based on a previous study that we had done called A to Z, and A was Atkins, and O was Ornish, and Z was zone, and T was a traditional health professionals diet. And in the original study, Comparing a bunch of very popular diet books that were New York Times best sellers other than the traditional approach, 75 women each, 300 altogether for a year had tried these books. And the difference between the diet was Just a few pounds, but the difference within each diet was 60 pounds. Somebody getting the same advice had dramatically different results than somebody else. And very specifically from the onset, we said, We know in this world of trying to lose weight, that there's a calorie balance issue. And what we really want you to find is a diet approach that you don't just do for this study, but you maintain afterwards. If you only do it for the study, if it's If it's only a diet you go on and then a diet you will go off when you're done, that won't help.

It has to be something that you can maintain. So we don't want you to be hungry. We want you to eat till you're satiated. And if you are still hungry, we're going to ask you to look us in the eye. You're not done. You might have to add on your low carb diet more carbs back or on your low fat diet more fat back. It has to work for you. Socially, you can't be hungry all the time. They lost 6,500 pounds collectively. They lost 12 pounds on average. And in the end, we saw the same thing on healthy low carb and healthy low fat. Somebody gained 15 pounds and somebody lost 50 pounds and everything in between. It's this huge range of variation.

I want to make sure you got that. Even when following the same diet, some people gained 15 pounds and some people lost 50. The same diet followed closely to make sure it was the same diet, and it still had this huge difference. Why? Well, Professor Garner believes there is another absolutely critical predictor of success, and that is not only how much you are eating, but how hungry you are after you eat. It's called satiety. Do you actually feel full?

I haven't quite figured out how to do this study yet, but I think it's hugely satiety or satiation. There's two aspects of this. One is stop eating sooner. Now, I'm going to miss the word on this. There's a great Japanese word for eating till you're 80 % full. Harahachi bu. Thank you very much. Okay, so that's the word I knew I was going to blank on. And then the key is, when is your next meal? So are you satiated for a long time? You'll hear some people say, I had this thing and it was great, but oh, my God, an hour later, I was hungry and I had to eat again. So the key to this calorie deficit is stopping your meal soon enough to not over eat and having a long enough space till the next meal so you're not making up for that calorie deficit in the next few hours. I think satiety is a huge factor here. I often ask people in some of my talks, would you be more full and for longer on steel-cut oats with nuts and berries or with cheesy eggs? And Sanjay, I often get half the audience seeing one and half the audience saying the other.

It's actually surprised me how many times I've seen the room split. Like, these are very different breakfasts. I didn't test it. I just asked what their perception was, and their perception was very different.

And I guess the obvious question is, why do you think there is such a split on just basic things like that? Steel-cut oats, nuts, berries, things like that, versus cheesy eggs. I have my own answer, I think. But I'm just like, why the perception difference?

My hunch is there's something really about satiety that's different. If you choose It's healthy. So everything goes out the window. If one group is choosing a healthy version of one diet and a crappy high sugar, high white flour version of the other, if they're both choosing the healthiest foods in that group, it will work for some of them, and it won't work for others. And I think there's some satiety or satiation here. And wouldn't you say, well, God, if you're so convinced of this, why don't you test it? And we have horrible metrics for satiety.

Now, for what it's worth, in my mind, I'm more of an oatmeal guy. But I think Professor Garner raises this really fascinating point that what we find most satiating can really vary. And that means it's It's really important to choose foods this way. The healthiest options, yes, but also the ones you know are going to be the most filling for you and your body. So how do you find the foods that are most satisfying, most satiating for you? I'll ask Professor Garner after the break.

I think I know how you're going to answer, but when you put it all together, is there a type of diet that does seem to be generally the most effective? Again, people will vary, but you talk about keto, you talk about paleo. There was an article that just came out today on intermittent fasting. What do you think? And maybe I'll take even a step further and ask, what do you do? How do you eat with all that you know?

So my answer will be my diet is a whole food plant-based diet. Let me frame it this way. So there's another publication that's from maybe 2019, 2020 from the Journal of Medical Medical Association that I have been showing in almost every time I've been giving for the last few years. And it's very fun because it's American Trends of Protein, Carbs, and Fats over 20 years. In this particular paper, they started by showing proteins, carbs, and fats. And so the range has been very stable or the levels have been very stable over those 20 years. And it's pretty much around 18 % protein and around 30 % fat and around 50 % carbohydrate. And that's the main graphic. And then the next graphic is types of protein, types of carbs, and types of fats. And so the protein is almost always about 10 % animal protein and six or seven plant protein-ish. But call the plant 10 for now, just so that we have 10 and 10. Let's call it 20 % protein. The fat, very consistently, 10 % monounsaturated, 10 % polyunsaturated, 10 % saturated, 10 to 10. So that's 30. The carbs is about 10 % good healthy carbs.

So now we have 10, 10, 10, 10, 10 40. It hits you over the head. Everything else is 10. And the added sugars and the simple, quickly absorbed, refined carbohydrates are 40. And so here's my take. If you eat a plant-based, it could be vegetarian, it could be all the way to vegan. I'm happy to go into that, but I'd rather just say, whole food, plant-based, not a lot of junk food. If you were to get rid of all 40% of the added sugar and the refined grains that are the crappy carbs that are in this graphic, I posit to you that a couple of people would do great doing all that with healthy carbs. They just wouldn't have any more fat. This would end up being a low fat vegan diet. And a couple of, let's say I took 100 people. Two to 5 would be okay there. And then we got some keto people who are doing all that fat. They replaced all the 40 % with fat. So now it's a very low carb diet and very high fat diet. And 5 % would do great. And they'll be very vocal on social media.

And there will be a social media influencer to say that. But 90 % of the population would benefit it from some balance. So take those 40 % and make some of them healthy carbs, whole grains, beans. God, Americans don't eat enough beans. More beans, more vegetables, and some more avocado, some whole fat yogurt, some fatty fish, some nuts and seeds. So healthy fats and healthy carbs. Take that 40 %. And I think in that range, you would find different people succeed eating on what looks like very different diets because most of the 40 was fat or most of the 40 was carbs, but not all of it. The extremes only work for a couple of people, but they do. And they're very vocal when it works. But the US population would do best getting rid of the crappy carbs and adding healthier fiber-containing carbs and healthier unsaturated fats, which means you could Mediterranean around quite a range. But it's not all the package-processed crap that we get in the US, which is 40% of calories.

I've been a medical reporter for over 20 years now, and I feel like we try and give really helpful health content with regards to how people should nourish themselves. And I think that if you talk to people, I think they generally agree that the majority of our diet should come from whole plant-based foods as much as possible. And yet we still don't do it. It's not an information gap out there, I don't think. I think most people know what they should eat. What do you think is going on?

I think it's a food environment. 24/7, we're advertised with convenience foods that the food industry has made tasty. If you layer salt, sugar, and fat on top of each other in complex ways in inexpensive, convenient foods, it's really hard to turn those foods down. The old lace potato chip out of you can't eat just one was very intentional. It was made so it would fire dopamine reward pathways in your brain, and you would want another one. You couldn't have one cookie. You wanted the whole sleeve of cookies. Did you mean to do that? No, not really. So the most fun I've been having, Sanjay, is addressing this taste issue. So I think here's a huge problem in the US is that health and taste have been dissociated. You ask someone what they would like, and aspirationally, they would like to eat that way, but they like good food that tastes good. And they will tell you, I'd rather have the better tasting food than the healthy food, which is a little mind boggling to me because there's amazing amount of great tasting healthy food.

So with all the caveats you've given about calories, and they matter to a point, but after a while, your body starts to acclimate to reduced calories. So how much you eat and what you eat, we've talked about. What about when we eat? The merit to intermittent fasting.

So the intermittent fasting thing, the data, I don't know how much time we probably don't have another hour to go into this, but the data are not very compelling, in my opinion, for intermittent fasting. And part of the reason it's not compelling is because of all the versions. So if I could just quickly run through the Valt or Longo, five days of fasting a month out of 30 days. Or another type is a full fast for two days a week out of seven days every week. What seems like the more popular is the type of fasting that's within a 24 hour period. It's called time restricted eating. It's either a normal window of eating might be 16 hours for a person. So 12 or 10 or eight would be time restricted eating. Seeing that they stick to that can be a little difficult, but I haven't seen any studies where they've really compared the eight hour to the 10 hour to the twelve hour window. For what and for how long? Is it for weight or is it for fatigue or is it something else? It's a hard thing to study and publish with clean results.

Of the studies that are published, I'm not really very impressed. And I am very concerned because the intermittent fasting, the allure of it, as I understand it, is of all the things that your listeners have been hearing me say today. Like, oh, God, that guy from Stanford is so frigging confusing. He said everything under the sun. There's too many rules. Intermittent fasting, you look at your watch. Is it time to eat? No. Okay, I'm not going to eat. Wait, let me look again. Oh, I get to eat now. And there's no No emphasis on quality. So if it's just a window, I fear that people say it's the window so I can have the pint of ice cream or I can have the cookies or I can have whatever, because the most important thing is the window. And I really appreciate how simple that rule is. And it is really helping me because I'm not eating the rest of the day. And it is a trick to help me achieve that calorie restriction by just saying, it's not time to eat. And you alluded to this before. There's actually two terms, appetite and hunger. Hunger is a physiological state.

Appetite is, I could eat something. I just saw a billboard. I'm actually full. Or we all know that second stomach we have. I'm full. I couldn't have another bite of dinner, but dessert? I could totally have dessert. I have a second stomach. I don't have hunger for dessert, but I have an appetite for dessert because you just showed me the dessert tray, which is so undermining.

Look, I've done so many interviews about this topic, but this point that you've made a few times now about satiation, which makes total sense to me if it fits. I think that that's a really important takeaway here. To add a little bit of texture to it, to remind the audience that it takes a little bit of time, again, for satiation to set in. With the Harahachi Boo, the reason that they said, eat till your 80% full is because within a certain amount of time, 15, 20 minutes, whatever it may be, you will feel 100% full. So never stuff yourself, which I think... I don't think that's the one size fits all dietary plan that people probably want, but I think it goes a long way. Obviously, pay attention to how many calories you're eating. Pay attention to the quality of the calories that you're eating. Maybe if you care about it, pay attention to when you're consuming those calories. But for the most part, let Does your brain and your stomach work in some harmony here. It's a system that works if you let it, it sounds like.

Totally agree. And I have one more tip for the listeners here. It's something that I hope you'll like the phrase stealth nutrition. Stealth nutrition is actually something I learned from teaching Stanford students. And a colleague of mine and I, Tom Robinson, decided to teach a class called Food and Society. And we shook hands and say, We won't ever talk about health. He's a pediatrician. I'm a nutrition scientist. We're only going to talk about the environmental consequences of food, animal rights and welfare, human labor issues and slaughterhouses and the way fast food workers are treated. And we're not even going to find scientific papers. We're going to find popular books by Michael Paulen and Marion Nestle and Eric Schlosser and Jonathan Saffer-Fohr and have them. It's going to be a discussion-based class, and we're just going to find the readings for them and let them discuss them. Almost every student in the class changed their diet. Some went vegetarian, some only bought grass-fed beef because of the environment. Some of them stopped going to fast food restaurants. Never for health, all for these other reasons. And so I really like the frame of stealth nutrition, not in a deceitful way.

So the stealth part isn't deceiving them. The health part is pointing out how many societal consequences are to your food choices. Imagine that you started your diet for the week and you You see that chocolate chip cookie and you say, I can really start the diet tomorrow. I don't really have to start today because if I wait one more day, it only affects me. Once you take this course, the students say, Oh, my God, my food choices affect society. So if you have these societal impact influences out there to help you stick with that choice you're making. So please, let's put healthy and good taste back together. Let's think about societal chemical impacts of that, and let's biohack our satiety a little bit. I think those hints would go a long way.

Those are great takeaways, Professor. And It rings true. I think about a plant-based, the whole food diet for my health. You and I both share this concern about heart disease. Again, with my three teenage daughters, when I talk to them about food, they echo exactly what you said. It's interesting. They care about the world. They care about the environment. I said, Look, how much water it takes to make a hamburger, whatever it might be, whatever thing clicks with them. And they really take it to heart. I see it how it affects their food choices. And again, they're not thinking about health, and they're not even thinking about weight. They're thinking about a larger ecosystem, which is, I think, actually inspiring if young people are thinking that way.

Yeah. I really think that's true. And if you start thinking that way about food, I'm hoping to start thinking that way about Democrats and Republicans and war and this broader thinking about food, more sensible, will just feed in to some of the other issues in the world. And we'll all sit down and have a great tasting healthy meal together.

I got to say, I really enjoyed that one. I enjoyed the conversation with Professor Garner. I learned a lot. Think about calories, yes, but also really think about the foods that make you feel full. Really pay attention to that. Coming up next week on the podcast, we're going to talk to someone who's been doing a lot of thinking about diet culture. Actress and activist Jamila Jamil.

It's not a noble crusade.

I'm just protecting my mental health.

I don't want to see images of what I could look like if I were more attractive and perfect.

That's not good for anyone. That's coming up on Tuesday. I hope you'll join us. Chasing Life is a production of CNN Audio. Our podcast is produced by Erin Mathieson, Jennifer Lye, and Grace Walker. Our Senior Producer and Showrunner is Felicia Patinkin. Andrea Cain is our Medical Writer, and Tommy Bazarian is our Engineer. Dan Dizula is our Technical Director, and the executive producer of CNN Audio is Steve Lichten. With support from Jameis Andrest, John Dianora, Haley Thomas, Alex Manasari, Robert Mathers, Laine Steinhart, Nicole Pessereau, and Lisa Namarot. Special thanks to Ben Tinker, Amanda Sealy, and Nadia Konang of CNN Health, and Katie Hinman.