Traditionally, obesity was attributed to too much food intake and lack of exercise. Another possibility, however, is that the rise in obesity in developed countries is related to the increase in environmental chemicals over time. Research into chemicals, called obesogens, which may interfere with the body's natural ability to store fat, has indicated this can occur in laboratory animals.
In humans, hormones regulate fat storage in the body, whether from fat in the diet or from other sources that it turns into fat. Overall, the system that regulates all of the body's processes, from fat storage to sleeping, is called the endocrine system. It is a complex system that uses hormones as signaling molecules that keep the body functioning properly.
Obese and overweight people have more fat stored on their body than people of a healthy weight. All of this fat is stored in specialized cells called adipocytes, or simply fat cells. When a person eats more food than he or she needs to keep the body running, the endocrine system signals to the body to store the extra energy in the fat cells.
Most health information, at present, accepts that people get fat when they take in more than necessary, and then do not do enough exercise to burn energy off. The idea of obesogens does not contradict this, but also points to a chemical cause of obesity. Dr. Bruce Blumberg of the University of California Irvine in the U.S. first used the name "obesogens" for chemicals that could be implicated in the development of obesity.
Dr. Blumberg and some other researchers, as of 2011, reported that chemicals that enter the body can affect the normal functioning of the endocrine system. Instead of placing blame on the advent of fast food and other high energy foodstuffs, proponents of the obesogen theory think that chemicals, such as pesticides, food additives and compounds present in plastics can make the endocrine system store more fat than usual, and therefore cause obesity.
Animal studies indicate that some artificial chemicals are capable of affecting endocrine system function and fat cell growth. Fetuses also develop fat cells in the womb, and chemicals may potentially cause the fetus to grow more fat cells than normal, giving the baby more storage capacity in later life. Research is ongoing into the possibility that chemicals play a significant role in obesity. Most health organizations as of 2011 do not subscribe to the theory of obesogens. They recommend a healthy diet and exercise for obese people.
