Catherine Falls / Getty Images:
It is an eternal question. Which diet is best for losing weight? Or what should we eat (or avoid) to stay healthy?
Paleo or keto devotees will talk to your ear about why their diet is more sensible. People who choose vegan diets (non-animal products, including dairy products) are convincing for both personal and global health.
Duke University evolutionary anthropologist Herman Ponzer argues that human metabolism developed to the point where how we eat, we burn our calories, it’s more powerful than all our collective mania what? eat.
In his new book, Burn. New research blows eyelids on how we really burn calories, stay healthy հ lose weightPonzer breaks down the science of metabolism and tells stories about calorie expenditure in hunter-gatherer societies.
One of the most amazing findings is the concept of compressed daily energy consumption. The idea is that the human metabolism adjusts to the level of our activity to burn our daily calories in a surprisingly narrow range, no matter how hard you work. But do not let that depressing fact keep you away from the gym. You may still be exercising daily to maintain a healthy weight.
This interview with Ponzer is adapted for him interview: For Tulsa Public Radio Medical Monday The program և has been edited for length և clarity.
In your book, you deny the general metaphor we use for calorie expenditure: engine or car. You say that it would be better to compare it with running a business. Why is that?
The look of the engine leads to several things. We fill our bodies with fuel in the form of food. And we burn it in every task of our body by burning engine fuel.
But the engine, like your car engine, does not make a decision how it burns fuel. Combustion of a car’s energy is all about how hard you walk the gas pedal. Your body is not like that. Your body is more like a business because it has a common goal, just like any other business. The overall goal of your body is to survive and reproduce, because that is what every organism has evolved to do. But there are many parts, parts, sections that serve that common purpose.
In business you have finances, sales, human resources և security ամեն everything else. Your body is the same. You have all these different organ systems that all work together. And like business, when you have little income, you can do things around the clock. So you spend less on this or that task. And when all goes well, you can increase the energy you spend on different tasks. And so, such juggling or prioritization by the business is the same as what your body can do – how it burns calories.
One mistake with the calorie burner model is that we’re fine, I’m forced to burn more calories than I’m eating, either by eating less, or by exercising more, or both. But as you say, the metabolism adjusts,, lose weight becomes more difficult. So while exercise is not really a weight loss strategy, it is still very important for your overall health, isn’t it?
It is true: If you are more physically active, you will not burn more calories per day, but you will change the way you burn calories. If you burn calories on exercise, it means you burn fewer calories on other tasks.
And for many of us, that’s a really good thing, because if we spend less energy, for example, on inflammation, we reduce the level of inflammation. If we spend less energy on stress reactivity, for example, cortisol levels do not rise as high, և adrenaline levels do not rise, we achieve a lower level of stress response. And it seems that these exercises can also help keep testosterone levels for men or estrogen levels for women at a slightly healthier level. So that adjustment, the metabolism adjustment that we do, the exercise is so good for us.
You have done extensive research with modern hunter-gatherers, such as the Hadza people of Tanzania, to better understand how human metabolism works. What did you learn?
Hatsan still has no household crops, animals, cars, weapons or electricity or anything like that. They live in grassy open savannah houses in northern Tanzania. And every morning they wake up, և women are released to get vegetarian food, such as berries ար tubers. Men go hunting for wildlife using a bow and arrow.
For someone like me who studies how people evolved, such a community is simply an invaluable way of asking what hunting և does to our bodies. Because we humans have evolved over the millennia as hunter-gatherer species. Yes. Food may sometimes be scarce in such a population. And you always spend a lot of energy on physical activity. So your body really needs to master the priority of how it burns its calories.
Hadza walks wherever they go, համեմատ compared to us, they are rarely sedentary. I guess they burn a lot more calories than we do in a day. Surprisingly, your work shows that their metabolism is not so different from that of a normal American.
About 10 years ago we went and measured how many calories men and women in the Hadza community burn every day. Hadza is so physically active that we expect their total calorie burn to be much higher each day than we see in other industrialized populations in the United States, Europe, and beyond. And instead, what we found was that in fact, although men do 19,000 steps today, women do 13,000 steps a day, in addition to all the other work they do, they do not burn more. general calories every day than we do in the West.
Physical activity eventually becomes one of the things the body can move and regulate. And just as your body can adapt to changes in your eating environment, your body can adapt to changes in your physical activity. Thus, for Hadza, their “metabolism business” has been adapted so that they spend less on other body systems to accommodate the heavy physical activity load they have.
What does this mean for someone trying to lose weight today?
If you or I started an exercise program tomorrow, we do will Burn extra calories from that exercise for a moment. But in a few months, our bodies will be adjusted so that we expend about the same amount of energy every day as we did before we started exercising. Your body regulates how it expends its energy to keep the total calories burned each day in a relatively narrow range. It just speaks to how adaptable և our bodies are, how we do not actually control our metabolism the way we think.
You include a passage in the book about the TV show The biggest loser in which competitors competed to see who could lose the most weight. What was the problem?
The contestants took part in this performance, underwent intense exercises, which were almost accompanied by hunger. That way you can lose a lot of weight. But it is not stable. Your body pushes hard, cutting its metabolic rate. Some of those participants came back years later. People who have been able to lose weight still have lower metabolic rates than they used to. Many contestants regained their weight.
It shows you how to tackle the obesity crisis socially [to lose and keep weight off] It is not the approach of some big, drastic accident. You need to go more steady than that, because your body will just fall back if you push too hard.
So, if your goal is to lose weight, nutrition will have a greater impact than exercise. But is it necessary to exercise to maintain a healthy weight?
That’s right. Let’s review what the exercise does. I call it the rhythm part of your body. Ex exercises keep everything on the same page, on the same stroke և it helps to regulate your body work. And so, when you reach a healthier weight, when you can lose weight, get to the point where you want to be, exercise can really hold you back. Erc exercises change the way your body adjusts to how hungry you feel or how full you feel.
The Paleo diet is based on the idea that when we were all hunter-gatherers, we ate some eggs և had no problems with obesity or type 2 diabetes or high blood pressure. But based on your research on Hadza, what is wrong with the people of Paleo?
If you go out and have the opportunity to live with a band like Hadza, you realize that many of the stories we tell ourselves about the past, including the paleo diets, are just kind of falling apart. So, in the world of paleo diet, there is the idea that there is a kind of natural human diet, և that diet was very heavy with meat, it hardly had any carbohydrates at all և, of course, there is no sugar.
[In reality] Hadza has a mixture of plants and animals in its diet. It changes from year to year, but about half of the calories come from plants. And not only that, but something like 10 in reality[%] About 20% of their daily calories come from wild honey, which is just sugar և water, you know, which would not be on anyone’s paleo diet. Another big part of their diet is starchy tubers and root vegetables, which are often forbidden to eat in some versions of the paleo diet.
One last thing surprised you about your book. You write about the metabolic rate of pregnancy compared to pregnant women on the Tour de France.
You can push your body like in the Tour de France, where riders burn 7,000 or 8,000 calories in three weeks. But it does make sense that pregnancy pushes the same metabolic limits as the Tour de France. They both drive your metabolism completely as long as it can maintain it. It’s just talking about how much pregnancy’s are taxed for one thing, but it’s all about what those things are. Our energy machines work together on these different tasks, creating connections that unite all these different experiments.