If not because of some disease reasons, from the simplest reason, obesity is the result of imbalance between energy intake and consumption of human body, that is, energy intake is greater than energy consumption, and as a result, energy is stored in the body in the form of fat, and after a period of time, weight increases significantly to form obesity. In the early stage of obesity, the fat cell volume becomes bigger, and with the increasing weight, the number of fat cells starts to increase, and it is very difficult to treat obesity at this time. Some studies found that after losing weight by dieting or restricting energy intake, the number of fat cells does not decrease, so when normal diet is resumed, the weight also returns to the state before weight loss. Generally obesity in the following periods is very difficult to cure. c obese children from 12 to 18 months after birth; c obese people from 12 to 16 years old; c obese people whose adult weight exceeds 60% of ideal weight (or body mass index greater than 40); c obese people whose women are obese during pregnancy and whose weight is not restored after delivery; because obesity in each of the above periods has a more obvious increase in the number of fat cells, so It is more difficult to treat. But why eat the same diet some people are fat, and some people are not fat? It is because there are differences in the following factors. Dietary factors Dietary factors are the key factors in the pathogenesis of obesity. The root cause of obesity is that the calorie intake exceeds the calorie consumption, in line with the “disease from the mouth” reason. So no matter what to eat, as long as the total calorie exceeds the body’s needs, will be fat. But why do some people gain weight even if they don’t eat much? This is when you need to consider the proportion of different varieties in the diet, consuming too much fat components can promote the growth of adipose tissue, especially saturated fat. Saturated fats are mainly derived from animal fats, but vegetable oils in general also contain a large amount of saturated fatty acids, and the “excessive heating” during the cooking process also oxidizes the originally small amount of unsaturated fatty acids into saturated fatty acids. Excessive calorie intake is always associated with excessive fat intake, because the same amount of fat is much more efficient in carrying calories than the same amount of starch and protein, so “not eating too much” does not mean “not eating too many calories”. In short, the improvement of living standard, the improvement of diet is the important reason of obesity. Environmental factors environmental factors mainly refers to people’s social environment, living habits, fashion, etc.. Yang Guifei era of “fat for beauty” naturally determines the pursuit of fashion people’s lifestyle. And the American lifestyle will make people fat, the United States “Coca-Cola” or “McDonald’s type” of diet and lifestyle habits determine the incidence of obesity in the United States nearly 30%. If you drink sugary drinks and eat fast food at a meal, the calorie intake is much higher than a regular diet when you are full. Therefore, the more “Americanized” lifestyle, the higher the possibility of obesity. Likewise, social competition, psychological stress, anxiety, etc. are changing people’s lifestyles, but unfortunately these changes all tend to make people fat.