On a hot summer day, eating ice cream is enough to enjoy yourself. In the cinema, if there is no delicious popcorn, then watching the movie will not feel. Open the desk drawer, all kinds of biscuits, chocolates and nuts also seem to remind us where our work energy comes from. But do you know that a tin of drinks contains 10 spoons of sugar? The more honest the taste, the higher the fat content of ice cream, All kinds of cakes and fast food provide calories and at the same time give us an overload of fat. You may say that vegetable salads are always healthy, but the salad dressing and Thousand Island dressing in them contain no less fat than the above foods. Why do we always covet foods rich in fat and sugar and cannot stop? Why is it that when we are already full, our appetite can make room for the last dessert? Why do some people suffer from obesity due to excessive diet? Why do other people suffer from eating disorders and do not hesitate to pay the price of health to lose weight? In order to answer these questions, we need to consider the specific needs and motives hidden behind these behaviors. First, why [eat]? If you ask why we eat, I’m afraid in the newborn baby, We can also find the reason. We eat because we are hungry and need. Eat, Not just physical behavior, It also has psychological significance. We eat because we like food. This motive is pleasure. We get pleasant feelings from sight, smell and taste. From the process of eating to feel the beauty of food. Therefore, Food is the most common and common way to get happiness. It is also necessary for our survival. People love food, This is also a great evolutionary advantage. Our ancestors evolved in the barren prairie for millions of years. Daily activities require a lot of calories, But there is no chance of unlimited calorie intake. In this case, In order to keep your weight and appetite within the best range, We have evolved an effective biological control system, Can keep us stable and healthy weight. Second, eat, It’s instinct. If you’ve ever been on a diet, There will definitely be this feeling: The body will always try every means to thwart your efforts to lose weight. Researchers also found that in experiments with laboratory rats, Severe caloric restriction will reduce body fat in rats, However, once the rats were allowed to eat freely, It will eat all the time, Until the original body fat level is completely restored. And vice versa, Those rats whose body fat increased due to forced eating, Once you have the opportunity to adjust your food intake, They eat less, Until normal body fat levels are restored. This behavioral response of rats, It is a mechanism to maintain energy homeostasis. The correlation between body fat and feeding behavior also seems to suggest that, There must be some kind of information exchange between adipose tissue and brain. So today, When you want to lose a lot of weight and want to stay fat, It is tantamount to fighting against the evolutionary ability of human beings for millions of years. Three, whether to eat or not, The hypothalamus has the final say. Almost all physiological processes in the human body are monitored and influenced by the brain. So we can speculate that, The brain may regulate body weight by affecting appetite, physiological activities and energy distribution. Studies have found that the hypothalamus, which is located at the base of the brain, is such a center for regulating energy. The brain can learn information about body weight from the body. According to this, appetite and energy consumption are regulated. The place where this information is received is the hypothalamus, which plays the role of controlling appetite, and one of the causes of eating disorders may lie in this. One of the hypothalamus regions is called the lateral nuclei, which is responsible for sensing the decrease of blood sugar and sending out [hunger] signals. The other site is called ventromedial nuclei, Responsible for raising blood sugar concentration, Send a full signal. Through surgery, A small hole was made in the lateral area of the hypothalamus of rats in the laboratory. Rats act like they don’t eat or drink, Increasing energy consumption, They are getting thinner and thinner. Providing them with food, Unless plugged, Otherwise refuse to eat, Until they die. On the contrary, when the ventromedial nucleus of the hypothalamus of rats is damaged, they will show hunger, overeat, reduce energy consumption and gain several times of weight. In clinical practice, patients with hypothalamic tumors will also show the same phenomenon. Therefore, after the hypothalamus is damaged, people’s eating behavior will have great changes. Four, eat! This is what dopamine says to the hypothalamus. Like all our desires, The center that controls the feeding mechanism is also in the hypothalamus. After all, We always crave the food we like. When we are eating, Through the complex interactions of hormones and neurotransmitters, Constantly transmitting information to the hypothalamus. In the process of forming the motivation of eating, Dopamine plays a very important role, It can make people feel happy. In fact, Many of our desires, Such as appetite and sexual desire, In the end, it is all satisfied by dopamine. The power of dopamine is that, It can stimulate thoughts, feelings and meaningful connections with the outside world. For example, Thinking of food, We will yearn for something to eat in our mouth immediately. It drives us to fill our desires and appetites. If this drive does not stop, We become addicted to it. The dopamine release we show when we eat, Believed to be a reaction to delicious food, Its release will make the eater feel happy. Some studies on experimental animals show that Dopamine pathway is involved in mammals’ handling of eating pleasure. 5. Dopamine tells you: More, more, And… When people eat, Brain cells begin to secrete dopamine, Make people feel happy, In this way, people will have the motivation to continue to do it. It can be said that, Dopamine is the candy of the human brain. But the function of dopamine, a neurotransmitter, More like a [driving force], But not real happiness. This seems to have nothing to do with people’s claimed [love] for a certain kind of food. The dopamine circuit in the brain is called the reward circuit, From the ventral tegmental region to the nucleus accumbens, amygdala, diaphragm, and then to the prefrontal cortex, this circuit is called the medial forebrain bundle (MFB). When this circuit is stimulated by dopamine, the nucleus accumbens will make the body want what we want and regulate intake and swallowing. The amygdala confirms its value and produces a feeling of excitement. The prefrontal cortex and septum focus our attention on this target and prepare for foraging behavior. The somatosensory cortex carries out taste perception. As a result of their cooperation, Is that we have a pleasant climax, However, it does not produce permanent satisfaction. The secretion of dopamine makes us feel like we need, need, need, etc., which is the basic mechanism of psychological addiction. Therefore, dopamine has nothing to do with how much we want something, but not how much we like it. Six, why do we love foods high in sugar and fat? Then why is it that foods rich in fat and sugar are irresistible? To answer this question, We need to trace the roots of human evolution. 1. Ancestors’ eating habits and regular famines at that time, The diet of our human ancestors was basically vegetarian. There is very little fat (meat is very rare, Even if there is, Also usually very thin meat), There is very little sugar, Sweets are even rarer (usually only ripe fruits and wild honey), There are few foods that are rich in water and fat and can be quickly chewed and swallowed. More importantly, Intermittent famines often occur in many places, Therefore, when there is an opportunity to get high-calorie foods rich in fat and sugar, Naturally, you should eat more, To accumulate body fat, Plan for the bitter days ahead. This kind of eating habit of ancestors, Causes us to naturally like certain smells and tastes, The most obvious ones are fat and sugar. When eating such foods, Activation of the ventral tegmental area of the brain and dopamine release from the striatum will both increase. 2. Food preferences left over from modern people Interestingly, The combination of fat and sugar is the most addictive, The stimulus to the reward circuit is much greater than the separation of fat and sugar. Today, When we eat foods rich in fat and sugar, The brain’s reward circuit activity will increase. At the same time, It also promotes the striatum to produce endorphin, This chemical can also enhance our sense of pleasure and reward, Let’s [feel good]. 3. The more we eat, the more we want to eat. It’s a sign of addiction. For some people, Dopamine, endorphins and other chemicals that control the brain’s reward system, It suppresses the signal to stop eating when you are full, This will still create a strong motivation for eating high-calorie foods. The more you eat, The more I want to eat, This is also a common feeling in drug addiction. Not only the mice in Skinner’s box (Skinner’s experimental equipment designed to study operational conditioned reflex), Will try to keep pressing the bar for oily and sweet food, Even mice that have eaten laboratory food, When it comes to sweets or greasy foods, And eat more. In fact, at this point, We don’t need animal experiments to know. Everyone has had this experience: You just had a big meal, Clearly too full to eat another bite, But when delicious cakes or ice cream appear, But you can eat this [last sip]. As you eat more and more, Weight is also increasing. In order to resist those attractive external signals, The body produces more appetite-suppressing hormones, Such as leptin and insulin. However, The effect of these hormones will gradually decrease, Because the human body is tolerant to the effects of these hormones. Seven, overweight people eat more to feel happy. Brain imaging studies show that the brain reward system of overweight people is weak to food, even attractive junk food. Suppression of the reward circuit will make overweight people depressed. How to overcome this mood? Only by eating more delicious food, In order to obtain temporary happiness. This forms a vicious circle: Overweight people only eat too much, In order to experience the pleasure that ordinary people can enjoy in a normal diet. Therefore, Obesity does not stem from what we usually think is a lack of willpower and self-control, In some cases, Obesity is caused by hedonic overeating [manipulating] the brain’s reward system. Just like drug abuse, Excessive eating establishes a feedback loop in the reward loop: The more you eat, The stronger the appetite, And satisfying this appetite will become more and more difficult. Laboratory rat experiments also support the above view. Those obese rats, Despite the warning of electric shock, You can also eat too much. Similarly, Many overweight people have struggled fiercely with bad eating habits, Even by hurting one’s own body, Such as vomiting after eating, So as to control diet, But in general, They will all [relapse], If you eat too much again, Then they get fat again. This gives them a short-term pleasure in their bad habits. Then try to get rid of it, and finally relapse. Eight, sum up the desire to eat and drink, can be adjusted by many factors, social culture determines human eating conditions and habits, but also shapes the psychological state and cultural customs related to food. Bad emotional state and stress events will lead to obesity due to extra eating; Environmental cues are also an important reason to arouse desire and relapse. Exposed to the eating habits of family members, friends and colleagues, they are repeatedly teased and tempted by delicious food. In today’s society full of fat and temptation, it is a long way to go for any overweight person to lose weight.