Genes have an important role to play in obesity. It is often witnessed that obesity runs in families. Genes along with lifestyle and dietary habits are usually responsible for that. Studies have clearly revealed that over 200 genes and gene makers cause obesity among which leptin is probably the most effective of all. It acts as a natural bone inhibitor and conveys information to the brain about slowing down the bone formation rate. Along with that, leptin is also concerned with maintaining metabolism and appetite of an individual.
Findings show that overweight people have a high leptin level in the blood. A number of diseases can be caused by the shortage of this particular obesity gene such as overeating, immune dysfunction, several neuroendocrine abnormalities and impaired thermoregulation. It can even come in the way of sexual performance. These medical conditions play an instrumental role in facilitating weight gain. Again, there are other genes like INSIG2 or insulin induced gene 2 which can produce excess fat thereby resulting in obesity.
There is another important gene that has an intrinsic connection with obesity. It is FTO or Fat Mass and Obesity associate gene. It is a gene that is a part of human chromosome 16 and is mainly of two types. First one comes with one high risk genes copy while the second one possesses two high risk genes copy. Maximum number of people has one high and one low risk FTO gene. You can also find some who possess both the copies. Generally, people having two such copies are more likely to gain weight than those possessing one. Any flaw in these two copy genes also results in several health problems along with obesity such as metabolic syndrome and Prader-Willi syndrome.
However, it is also true that genes cannot be held totally responsible for weight gain or obesity. There are other factors as well. For instance, lifestyle choices and habits also matter. These are environmental factors that cannot be overlooked as far as finding the causes of obesity are concerned. Eating habits are often developed by what one sees around him.