Translator: Alisa Xholi Reviewer: Helena Bedalli Three and a half years ago, I made one of the best decisions of my life, As a New Year's decision, I gave up the diet, I started not to worry about my weight, and I learned to eat carefully. I already eat whenever I'm hungry, and I lost 4 and a half pounds. This is me at the age of 13, when I started my first diet. I see that picture now, and I think I did not need a diet, i needed a fashion consultant. (Laughter) But I thought I should lose weight, and when I retrieve them, of course I blamed myself. And for the next three decades, I have been on and off different diets. No matter what I tried, the weight I lost always came back.
I'm sure many of you know the feeling. As a neuroscientist, I wonder, why is it so difficult? Clearly, how much it weighs depends on how much you eat and how many calories you burn. Many people do not understand that hunger and energy use controlled by the brain, mostly without your knowledge. Your brain does the work behind the scenes, and that's a good thing, because your conscious mind – how can we say this politely? – easily distracted. It is good that you do not have to remember to breathe while being forgotten in a movie. He does not forget how to walk because you are thinking about what you are going to do for dinner. Your brain also has its own sense of how much you should weigh, despite your conscientious belief. This is called the starting point, but this is a misleading term, because it is currently a range of about 5 or 7 kg. You can use lifestyle choices to move your weight up and down under that game, but it is much harder to stay out of it.
Hypothalamus, part of the brain that regulates body weight, there are dozens of chemical signals in the brain that tell your body to gain weight, more than a dozen others who tell the body to lose it, and the system works like a thermostat, responding to body signals adapting urine, activity and metabolism, keep the body in stability while conditions change. This is done by a thermostat or not? Keeps the temperature of your home stable while the time outside changes. You can change the temperature at home opening a window in winter, but this will not change the definition in the thermostat, which will respond by promoting warmth to reheat the place again. Your brain works in exactly the same way, responding to weight loss with the use of powerful tools to push your body back in what is considered normal. If you lose a lot of weight, your brain reacts like you are very hungry, even if you are healthy or weak at first, your brain's response is exactly the same. We would like to think that your brain can tell whether you need to lose weight or not, but can not.
If you lose a lot of weight, then you start to get hungry, and your muscles burn with less energy. Dr. Rudy Leibel from Columbia University has discovered that people who have lost 10 percent of their body weight burn 250 to 400 calories less because their metabolism is suppressed. This is a lot of food. This means that a successful person in the diet should be fed less than that always than someone of the same weight which has always been weak. From an evolving perspective, your body's resistance to weight loss makes sense. When food was scarce, the survival of our ancestors depended on energy conservation, and weight recovery when food was available would protect them during the next absence. In the course of human history, hunger has been a much bigger problem than on nutrition. This may explain a very sad fact: Starting points can be climbed up, but rarely come down. If your mother ever mentioned you that life is not fair, this is more or less the thing about what she was talking about. (Laughter) Successful diets do not lower your starting point. Even after you have maintained the weight for more than seven years, your brain keeps trying to recover.
If that weight loss was due to constant hunger, that would be a sensible answer. In our modern world where we buy hamburgers without getting out of the car, it is not working well for many of us. That difference between our grandparents and the present where we have more is why Dr. Yoni Freedhoff from the University of Ottawa would like to get some of his patients back in time where food has been less available, and is also the reason than to change the food environment will be the most effective solution to obesity. Unfortunately, a temporary increase in weight can be turned into permanent. If you stay at a high weight for a long time, maybe a few years for most of us, your brain can decide that this is the new normal.
Psychologists divide hames into two groups, those who rely on their urine and those who try to control their eating between the will, like most of those on a diet. Let's call them intuitive and controlled hames. The interesting part is that intuitive hames are less likely to be overweight, and spend very little time thinking about food. Controlled hams are more vulnerable to overeating in response to advertising, of large masses, and of self-service buffet. And a small privilege, how to get a cup of ice cream, most likely to turn into an overeating in controlled hames.
Children are especially sensitive to this dietary cycle and then return to excessive hames. Several long-term studies have shown that girls who diet in the early teens are three times as likely to become overweight five years later, even if they started at a normal weight, and all these studies revealed that the same factors that predicted weight gain also predicted the development of eating disorder. The other factor, by the way, those of you who are parents, was harassment of family members for their weight. So do not do it. (Laughter) I left almost all of my graphics at home, but I could not resist without telling you this, because I'm obsessed, and that 's how it works. (Laughter) This is a study on the risk of death for a period of 14 years based on four healthy habits: eating enough fruits and vegetables, exercising three times a week, do not smoke, and mass alcoholic beverages. Let's start by looking at normal weight of people in this study. The height of the bars indicates the risk of death, and those zeros, one, two, three, four numbers in the horizontal axis are the number of those with healthy habits given to a person.
And as you can imagine, the healthier the lifestyle the less likely people are to die while studying. Now let's see what happens in overweight people. Those who had no healthy habits had a higher risk of death. Adding just a healthy habit attracts overweight people to the normal range. For obese people without healthy habits, the risk is very high, seven times higher than the healthier groups in the study. But a healthy lifestyle also helps obese people. In fact, if you will see the group with all four healthy habits, you can see that weight makes very little difference. You can take control of your health taking control of your lifestyle, even if you can not lose weight and keep it away.
Diets do not have much certainty. Five years after a diet, most people have regained weight. Forty percent of them have received even more. If you think so, the typical result of diets is that, you are more likely to gain weight in the long run than to get lost. If I convinced you that diets can be a problem, the next question is, what are you going to do about it? And my answer is, in a word, awareness. I am not telling you that you must learn to meditate or do yoga. But I tell you about conscious eating: to learn to understand the signals of your body so that you can eat when you are hungry and stop when you are full, because too much weight gain comes from I ate it when you are not hungry.
How do you do it? Give yourself permission to feed as much as you want, and then work to discover what makes your body feel good. Sit down to normal meals without distractions. Think about how your body feels when you start eating and when you stop, and let your urine settle when you should finish. It took me about a year to learn this, but it really was worth it. I am more relaxed about food than I have ever been in my life.
I often do not think that. I forget we have chocolate at home. It's as if aliens have entered my brain. It's something totally different, I have to say that this eating treatment will probably not make you lose weight unless you eat often when you are not hungry, but doctors do not recognize any treatment performing significant weight loss in many people, and this is why many people are now focused in preventing weight gain instead of promoting weight loss. Let's face it: If diets worked we would all be weak by now. (Laughter) Why do we keep doing the same thing and expect different results? Diets can seem harmless, but in reality they do an indirect damage. At worst, they ruin lives: Weight mania leads to eating disorder, especially in young people. In the US, we have 80 percent of 10-year-old girls who say they have been on a diet. Our girls have learned to measure their values to the wrong degree.
Even at its best, diet is a waste of time and energy. It takes willpower which you can use to help children with homework or to complete a work project, and since the will is limited, any strategy which depends on its sustainable implementation is more or less guaranteed to fail you eventually when your attention moves to something else. Let me leave you with one last thought. What if we told all these girls on the diet that it is ok to feed them when they are hungry? What if we taught them to work with their appetite instead of being afraid of him? I think most of them would be happier and healthier and as adults, many of them would be weaker. I wish someone had told me that when I was 13. Thank you. (Applause).