At an individual level, a combination of excessive food energy intake and a lack of physical activity is thought to explain most cases of obesity. A limited number of cases are due primarily to genetics, medical reasons, or psychiatric illness. In contrast, increasing rates of obesity at a societal level are felt to be due to an easily accessible and palatable diet, increased reliance on cars, and mechanised manufacturing. It affects a large percentage of world population. Staying sedentary can make you vulnerable to the condition. There are many other reasons for rising cases of the condition as you may find out in the E-Zine below. Certain food items may also be responsible.