Causes of Obesity
What causes obesity?
In many ways, obesity is a puzzling disease. How the body regulates weight and body fat is not well understood. On one hand, the cause appears to be simple in that if a person consumes more calories than he or she expends as energy, then he or she will gain weight.
However, the risk factors that determine obesity can be a complex combination of genetics, socioeconomic factors, metabolic factors, and lifestyle choices, as well as other factors. Some endocrine disorders, diseases, and medications may also exert a powerful influence on an individual's weight.
Factors which may influence the occurrence of obesity include, but are not limited to, the following:
- Genetics. Studies have shown that a predisposition toward obesity can be inherited. Although researchers have identified several genes that appear to be associated with obesity, most believe that one gene is not responsible for the entire obesity epidemic. The majority of current and future research aims to better understand the interaction between these gene variations and our ever-changing environment in the development of obesity.
- Metabolic factors. How a particular person expends energy is different from how someone else's body uses energy. Both metabolic and hormonal factors are not the same for everyone, but these factors play a role in determining weight gain. Recent studies show that levels of ghrelin, a peptide hormone known to regulate appetite, and other peptides in the stomach, play a role in triggering hunger and producing a feeling of fullness (satiety).
- Socioeconomic factors. There is a strong relationship between economic status and obesity, especially among women. Women who are poor and of lower social status are more likely to be obese than women of higher socioeconomic status. The occurrence of obesity is also highest among minority groups, especially among women.
- Lifestyle choices. Overeating, along with a sedentary lifestyle, contributes to obesity. These are lifestyle choices that can be affected by behavior change.
Eating a diet in which a high percentage of calories come from sugary, high-fat, refined foods promotes weight gain. And, as more U.S. families eat on the go, high-calorie foods and beverages are often selected.
Lack of regular exercise contributes to obesity in adults and makes it difficult to maintain weight loss. In children, inactivity, such as watching television or sitting at a computer, contributes to obesity.