In the cold season, eating spicy hot pot, drinking carbonated soft drinks, that feeling is really cool; hot summer, eating a big mouthful of ice cream is enough to enjoy; open the desk drawer, a variety of cookies, chocolate seems to remind us of the work energy from where. But did you know that a single drink contains 10 spoons of sugar? All kinds of pastries and fast food provide calories and also give us an overload of fat. Why are we always salivating and craving for food rich in fat and sugar? Why is it that when we are already full, our appetite can make room for one last sweet treat? Why do some people become obese as a result of overeating? To answer these questions, let’s talk about the original needs and secrets behind “eating”. Why do we love to “eat”? If we are asked why we eat, I am afraid that the reason can be found in a newborn baby. We eat out of hunger and need. Eating is not only a physical act, but also has psychological significance. We eat because we like food, and this motivation is hedonistic. We get pleasure from the senses of sight, smell and taste, and then we feel the wonderfulness of food from the process of eating. Therefore, food is the most common and ordinary way to obtain pleasure and is necessary for our survival. In order to maintain our weight and appetite in an optimal range, we have evolved an effective biological control system that allows us to maintain a stable and healthy weight. Eating, it’s instinctive! If you’ve ever been on a diet, you’ve certainly felt it: your body will always find ways to thwart your efforts to lose weight. Researchers experimenting with lab rats also found that severely restricting caloric intake caused the rats to lose body fat. However, once the rat was allowed to resume free-feeding, it would keep eating until it fully regained its original body fat level. Conversely, rats that had increased body fat as a result of forced feeding, once given the opportunity to regulate their own intake, would eat less until they returned to normal body fat levels. This behavioral response of rats is a mechanism to maintain energy self-stabilization. The interconnection between body fat and feeding behavior also seems to suggest that there must be some kind of information exchange between adipose tissue and the brain. So today, when you have to lose a lot of weight and try to maintain it without regaining it, you are tantamount to fighting against the ability of humans to evolve over millions of years. To eat! Dopamine says so to the hypothalamus! As with all our cravings, the center of the control mechanism for eating is located in the hypothalamus at the base of the brain. After all, we are always craving the foods we like. When we eat, the various parts of our body are constantly sending messages to the hypothalamus through a complex interaction of hormones, neurotransmitters, and more. Dopamine plays a very important role in the formation of motivation to eat, which leads to feelings of pleasure. In fact, many of our desires, such as appetite and sexual desire, are finally satisfied by dopamine. For example, the thought of food makes you crave something in your mouth right away. It drives us to fill our desires and appetites. If this drive doesn’t stop, we become addicted. Dopamine tells you: more, more, more …… When a person eats, brain cells begin to secrete dopamine, which causes a sense of pleasure so that the person will be motivated to keep doing it. It can be said that dopamine is the “sugar cube” of the human brain. But dopamine is a neurotransmitter that acts more like a “drive” than a real sense of pleasure. This seems to have less to do with a professed “love” of a treat and more to do with a level of “need”. The dopamine circuit in the brain is called the “reward circuit” and leads from the ventral tegmental area to the vomeronasal nucleus, the amygdala, the septum, and then to the prefrontal cortex. When this circuit is stimulated by dopamine, all of these areas of the brain work together to give us a pleasurable orgasm, but not a permanent sense of satisfaction. The secretion of dopamine causes us to feel like we want more, more, more ……, which is the basic mechanism of psychological addiction. So, dopamine has more to do with how much we want something and less to do with how much we like that thing. Why do we love high sugar and high fat foods? And why are foods rich in fat and sugar so hard to resist? To answer this question, we need to trace the roots of human evolution. 1, ancestral eating habits and every now and then famine At that time, our human ancestors’ diet was basically vegetarian, with very little fat (meat was very rare), very little sugar, and even less sweets (usually only found in ripe fruits and wild honey), and very little food rich in water and fat that could be quickly chewed and swallowed. What’s more, intermittent famines often occurred in many places, so when there was an opportunity to get high-calorie foods rich in fat and sugar, it was natural to eat more of them in order to hoard body fat and plan for future hard times. This diet of our ancestors led to our natural preference for certain smells and tastes, the most obvious being fat and sugar. When the intake of such foods, the brain’s dopamine release will be increased. 2. Modern food preferences Interestingly, the combination of fat and sugar is the most addictive, stimulating the reward circuitry much more than fat and sugar alone. Today, when we eat foods that are rich in fat and sugar, the brain’s reward circuit activity is enhanced. At the same time, the brain’s striatum will be prompted to produce endorphins, a chemical that can also enhance our sense of pleasure and reward, making us “feel good”. 3, the more you eat, the more you want to eat, which is a sign of addiction For some people, dopamine, endorphins and other chemicals that control the brain’s reward system will suppress the signal to stop eating when you’re full, so you will still have a strong motivation to consume high-calorie foods. The more you eat, the more you want to eat, a feeling that is common in drug addiction. In fact, this is something that we have all experienced in a similar way. You’ve just eaten a big meal and you’re too full to eat another bite, but when a delicious cake or ice cream comes along, you can always eat that “last little bite”. As you eat more and more, you gain weight at the same time. To counteract those tempting external signals, the body secretes more appetite-suppressing hormones, such as leptin and insulin. However, the effects of these hormones are gradually diminished because the body becomes tolerant to the effects of these hormones. Overweight people eat more to feel happy! Brain imaging studies have shown that the brain reward system of overweight people responds weakly to food, even tempting junk food. Inhibited reward circuits can make overweight people emotionally depressed. How can this mood be overcome? The only way to obtain temporary pleasure is to eat more food. This creates a vicious circle: overweight people can only experience the pleasure that ordinary people can enjoy in a normal diet by overeating. Obesity, therefore, does not stem from the lack of willpower and self-control that we usually assume, but in some cases, obesity arises because hedonistic overeating has “manipulated” the brain’s reward system. As with drug use, overeating sets up a feedback loop in the reward circuit: the more you eat, the stronger your appetite becomes, and the harder it becomes to satisfy that appetite. This allows them to take a brief pleasure in the bad habit, then try to quit, and eventually relapse. Exposed to the eating habits of family, friends and co-workers, they are subjected to the teasing and temptation of food again and again. In today’s society full of fat and temptation, it can be a long way for any overweight person to lose weight.