DoctorOz: Unpacking the Science of Metabolism

Blaming those extra pounds on a slowing metabolism as you age? Maybe not so fast. A groundbreaking new study turns that theory on its head and challenges everything we thought we knew about metabolism. For decades, we thought metabolism looked something like this. Let me walk you through it. You got babies and young kids. They've got high metabolisms. They burn tons of calories. Slowing, you know, that metabolism starts to slow down as you reach puberty, right? And that spike does actually occur in puberty, we thought. I know plenty of hungry teens in my house. You probably do too. And then, of course, that metabolism begins to slowly taper off afterwards until we hit about 30, at which point it begins to tank, right? Plummeting down. You ever say, I can't eat now the way I used to, right? Yeah, we've all been there. We're on the same page. But a pivotal new study led by Dr. Herman Ponser of Duke University has made a groundbreaking new discovery. He is here today to dispel the myths about metabolism. Herman, we have all been talking about metabolism the same way for decades. That's what I learned in medical school. You did too, probably. Why did it take so long to discover this truth? Yeah, well, what we thought we knew about metabolism was based entirely on estimates. So this study was able to put together all the data collected across labs all over the world to finally have a really big sample and a really clear picture of metabolism across the lifespan. So it's the first sort of clear roadmap for metabolism from infancy into our old age. All right, so let's take the wisdom that you shared with us in this important groundbreaking paper. Let's go back to the chart, and let's go over where we went wrong. So metabolism, it turns out, rapidly increases. Let's put the new curve up. Not from this chart, but from this chart, we'll see that metabolism rapidly increases until you're about a year of age, right? This is a precocious child walking early. And then it slowly begins to taper off, right? There's actually no spike in puberty. Kids are active or doing something else that burns off their calories. It's not because of their metabolism. And then until you hit about 20, the metabolism begins to come down. And then after that point, it doesn't change at all from age 20 to age 60. I'll say it again, right? From age 20 to 60, there's not much going on with your metabolism. And then after 60, it does start to drop, but not that fast. About 0.7% per year. Not a huge amount. So let's take a closer look at this. Again, from 20 to 60, your excuses are gone. Because it's at this stage, we begin to see the changes in our body shape. We're slowly packing on the pounds. Most people start this. But the metabolism, it's not different, my friends. So we lost that excuse. Sermon, you're going to have a lot of skeptical women writing into my show. So what should I tell them? What's your answer, your rebuttal for why they're putting weight on? I feel the same way they do. In my middle age here, I feel like my body is different than it was when I was in my 20s. But we know from this study that it's not the metabolism, right? It's not the calories that we're burning that's changing. So those changes in the way our bodies look and feel have to be coming from the food that we're taking in, the calories that we're eating, right? So in a way, this is really empowering. Because it says there's not some invisible force forcing you to gain weight as your metabolism slows. And instead, we can kind of take control of our diet, focus on the calories that we're taking in, and take control of our weight that way. Well, Emily, the good news is you have a lot more control over your destiny, thanks to this research. Let me bring in our show contributor, Dr. Jennifer Cottle. You're always great to have this conversation. You're with women in the exam room, you know, exasperatingly talking about their weight gain. What does this metabolism fighting mean to you and your patients? And by the way, I'm a woman too. So I have to tell you, I'm in this conversation. My patients come in all the time. They say, Dr. Cottle, when I hit 40, when I reached menopause, that's when I started packing on the pounds. That's what it must be. I'm in my 40s now, Dr. Oz, and I had attributed my weight changes to a little bit of what we thought. So it's not necessarily our metabolism that gives us not only more information, so at least we know now, but it also gives us ideas about things that we can change. So that's really important. There are some things still happening inside of you, outside of metabolism, like, for example, your hormones. Yes. That could be responsible. No, it's true. And hormones are nothing to play with, right? We know that hormones affect so many different things. They can affect literally how full or how hungry we feel. Of course, things like stress and lack of sleep or excess sleep, et cetera, can affect our eating habits. Hormones play a role. So I think it's important to sort of recognize all the different dynamics that are happening in our body. But, you know, this is really groundbreaking, honestly. I'm shocked and surprised, and I'm like, oh. Let's go back to the man we can blame for this information. Kermit, there comes a point when metabolism does begin to slow, again, around age 60. Why do you think that's the magic number? Yeah, well, it's one of the exciting things about this research. We used to think, again, you know, that you're slowing metabolism as you age is because maybe you're being less active or you're losing muscle mass. We know that people after the age of 60 tend to lose a little bit of muscle mass. And those things can contribute. But this study says, no, no, no, because we can actually control for those factors in our analysis. And we can say, no, the cells are actually slowing down in people over 60. And that's important to know because that gives us a target for therapies, perhaps, to maybe keep our cellular metabolism at that younger level faster for longer. So potentially, a target for therapies for anti-aging in the future. Well, congratulations on this groundbreaking work. So everybody at home, listen, this is good news for you because if historic metabolism isn't causing your weight gain in middle age, well, what is? When we come back, we're going to find out the key to fighting the pounds. And don't worry, it does not involve hitting the gym again. We just learned that from age 20 to 60, your metabolism stays the same. You heard me right, the same. It goes against everything we thought we knew about why we gain weight in middle age. I know you all have lots of questions. We're going to get to them. I'm back with Dr. Herman Ponser, the author of the pivotal study that has everyone talking to Dr. Jennifer Cottle, a member of our team. Let's get to the first question Carol sent in this video. Why could I eat a whole pizza in my 20s and not gain one pound? And in my 50s, if I eat one cheeseburger, my thighs will explode. If it's not my metabolism, what in the world is it? Dr. Ponser has an answer. He says sneaky processed foods would be the cause of our collective weight gain over the years. But that gets got a lot of layers to it. So Herman, please explain. Yeah, so if you look at the obesity crisis in America, right, the people gaining weight over the last few decades, and maybe even in your own experience, you've had this. You can see it goes right along with the amount of processed foods, ultra processed foods that Americans are eating. We get over half of our calories these days in America from ultra processed foods. And these foods are designed to be irresistible, right? They're actually engineered to be overconsumed. And so they push our brains in ways that, you know, it's hard to say no. You know, so for example, if you think about a non-processed food like broccoli, for example, you know, it's easy to stop eating broccoli, right? You get halfway through the bowl or you feel full and you're done. That same amount of calories as potato chips, it's really hard to stop. Well, we literally even say that, right? You just you can't have just one of some of the foods you love the most. So it does sort of turn on the right parts of your brain, which is why manufacturers make them. But there's other factors that play into this as well. The processing sometimes comes in ways we don't expect, like the breads we eat. Yeah, that's right. So you have to be careful, you know, if you're looking at shopping for bread, we know that bread can be a concern. A lot of breads are super processed, lots of added sugars, even added oils. That's a real concern. But they can even come in in forms that you don't expect, right? Oatmeal can be really healthy. But if you look at the prepackaged ready to go oatmeal, a lot of that is actually a lot of added sugar and other added flavorings that make them just as bad as other processed foods in some ways that could push us to overeat. All right, up next, we've got a question from Amanda. She's joining us via Zoom. Amanda, take it away. So metabolism may not change naturally as we age, but do we have the power to boost our metabolism with exercise or certain diets? That's the kind of question I like to hear. You want to do something about it. So, Dr. Hall, there's been some surprising findings around exercise in particular. Yeah, you're so right. This is the type of question I like to hear, too, right? But the thing about it is exercise does not necessarily increase our metabolism. Now, that's not to say that exercise is not a good thing, because we know exercise is important for the heart, for so many other parts of our body. We also know that muscle mass actually burns more calories than fat. So there's a million reasons to exercise. But understanding that exercise does not increase our metabolism, I think, is very important. I always tell folks that you can lose weight by what you eat. You can. But to keep that weight down, you need to exercise. But you're not going to lose weight with the exercise, at least by itself. This hasn't been true in my life anyway. I think a combination is best. That's what I recommend to my patients, is both. And Herman, you're the expert in this area. Did I get it right? Exercise by itself won't get you to lose weight? That's right. I think we have to think about exercise and diet as two different tools for two different jobs, right? Exercise for health is super important, but diet is your best tool for weight management. And how about all these metabolism-busting approaches like high-protein, low-carb diets? What are we hearing about them? You know, metabolism-boosting supplements and superfoods and all these diet wars about low-carb, high-protein, you know, I wish we'd move away from that. But the metabolism-boosting supplements don't work. I hope that was helpful. All right. Next question comes from Sheila and her husband, Mark. Take it away. My husband and I started a weight loss journey together. We exercise and we eat our meals together. But he's losing more weight than I am. Do men have a faster metabolism than women? Herman, what did the research find? And what should Sheila do to him to pay him back for losing more weight? Yeah, good. I don't know about the second one, but I know about the first one. So men do tend to burn more calories than women because men tend to be bigger and tend to carry more muscle and less fat. But after you account for that difference in size and fat percentage, men and women's metabolisms are the same, actually. So there's nothing special about men's metabolism that makes them faster. It's just that they tend to be bigger. And we know that the bigger people, you know, you've got more cells cooking along, you're going to burn more calories just by being bigger. So, Sheila, you'll have to take care of the penalty on your own, but I hope that answer is useful. Sounds good. Thank you. All right. Thanks for being here. Dr. Herman Ponsner's book is called Burn. Check it out.