Obesity can be caused by diet, genetics, environment, and abnormal endocrine regulation. It may also be caused by certain diseases such as hypothyroidism and hypercortisolism. 1. Diet: obesity occurs when energy intake exceeds energy consumption, long-term dietary intake leads to an imbalance in energy intake and consumption, which may lead to obesity. 2. Heredity: obesity has a tendency to gather in the family, and most of the primary obesity is the result of the superposition of multiple genes. 3. Environment: the influence of the work environment or living environment, excessive pressure may also lead to obesity. 4. Abnormal endocrine regulation: If the important hormones involved in the regulation of energy metabolism, such as leptin, insulin and other abnormalities, may lead to obesity. 5. Diseases: such as hypothyroidism, corticosteroidosis, etc., can cause secondary obesity.