Anyone can become overweight or obese if they take in more calories than they burn. Some factors that may make it more likely to become obese include:

• Genetics: There are several genes that influence how the body regulates its energy balance including how much you eat, how efficiently the excess is stored, and how calories are used during physical activity. Inheriting certain genes can make it easier for you to put on weight and harder for you to take it off. However, there are only a handful of people in which a genetic mutation virtually guarantees them to become morbidly obese.
• Family history: Having close relatives who are obese increases your risk of becoming obese too. This could be due to shared genetics or to shared environmental factors.
• Age: Older people are more likely to put on weight, in part because physical activity often decreases and in part because hormonal changes tend to reduce muscle mass and metabolic rate.
• Sex : Women are more likely to be obese than are men. This is probably due to the fact that women have lower metabolic rates than men.