Causes of obesity: genetic, metabolic, and endocrine factors

Obesity has many causes, and opinions vary widely. In today's technologically advanced world, new viewpoints are constantly emerging. However, current research suggests that the main cause of obesity is that the body absorbs more nutrients than it needs-what we commonly call nutritional excess. Alternatively, it could be due to insufficient daily energy expenditure, where the body takes in more calories than it burns, leading to excessive accumulation of fat tissue.

So, specifically, what factors lead to fat accumulation and weight gain? Current research suggests that it is related to factors such as genetics, metabolism, endocrine system, social environment, and dietary habits.

Heredity

Statistics show that if both parents are obese, their children have a 68-80% chance of also being obese; if only one parent is obese, their children have a 40% chance of being obese. If both parents are thin, their children have only a 10% chance of being obese. In daily life, it's rare to find a child whose parents are both thin and who is very overweight, or a boy nicknamed "stick figure" by his friends who has parents with large bellies. Furthermore, the medical community generally believes that genetic factors play a greater role in determining body fat percentage in girls than in boys. Scientists have discovered that not only is the shape of obesity hereditary, but the location of fat distribution and bone structure are also hereditary. For example, if parents have obese hips, their children are more likely to have obese hips as well.

Recent international research suggests that obesity is related to a group of brown cells in the body. These cells are a rich source of energy for the body, rapidly converting fat into heat. When the body's energy reserves are depleted, they can also seek energy in surrounding white adipose tissue. Due to genetic differences, the metabolic rate of these brown cells varies from person to person. If parents are obese, their children are likely to inherit this genetic influence, resulting in slower brown cell metabolism and less "burning" of body fat, making them more prone to obesity. Conversely, if brown cells metabolize quickly, even with a large appetite, obesity may not necessarily occur.

Some believe that obesity is related to muscle fibers. Human muscle fibers are of two types: slow-moving and fast-moving. Slow-moving fibers use fat as their primary fuel, while fast-moving fibers use glucose from the blood as fuel, without needing to burn fat. Therefore, for people who naturally have more fast-moving fibers than slow-moving fibers, even with vigorous exercise, weight loss will not be significant.

This shows that a high proportion of obese patients are obese due to genetic factors.

metabolism

Metabolism refers to the process by which the body utilizes fats, proteins, sugars, and other nutrients. If you eat too much, exceeding your body's needs, carbohydrates will be converted into fat and stored in the body. Before being absorbed by the intestines, fat is broken down into two parts: glycerol and fatty acids. Fat and carbohydrates alternately serve as the body's "fuel." People with excess nutrition not only convert large amounts of excess carbohydrates into fat, but also store most of the fat as fuel, leading to an increase in fat cells and obesity.

Obese individuals exhibit significant metabolic differences compared to those of normal weight. Experiments have shown that even when consuming the same diet, obese individuals have a more elevated overall metabolism than those of normal weight.

endocrine

Obesity caused by endocrine disorders is the most common among various types of obesity caused by disease. Obesity is most prevalent in diabetic patients. In urban areas, the higher the total calories, sugar, and fat intake, the higher the incidence of diabetes. Diabetes is divided into insulin-dependent (Type I) and non-insulin-dependent (Type II) types, with the latter being more prevalent and occurring mostly in adults over 40 years of age. Obesity is one of the main contributing factors to this disease.