In western societies and in the United States in particular, overweight truly is an epidemic. The numbers describing the overweight situation are extraordinary: in the US, a full two-thirds of the population is overweight and one-third are obese. With this type of health epidemic ongoing, with this number of people, it's a worthwhile endeavor to consider just what some of the reasons may be for the overweight problem.

In most cases, excess weight is a reflection of calorie consumption. There are exceptions to this, most notably in circumstances where some form of bloating illness has set in. Generally speaking however, excess body weight is directly attributed to food consumed. The formula isn't quite so simple as eating and gaining weight: it comes down to intaking more calories than get burned away by being physically active. Eating more food than is used for energy, in other words.

So then there are two factors in typical weight gain: food eaten and energy burned, or not burned. If energy goes unburned, it eventually gets stored as fat. A typical form of human energy is physical movement. Most humans to one degree or another physically manipulate their bodies. Performing this sort of physical manipulation takes energy. The level of energy required to physically move depends upon how much movement is actually undertaken. In the case of many people in the west, and in the United States especially, people don't move around very much in comparison to the level of food they intake. What we have then are lots of people who consume more energy than they use.

The energy factor in overweight can be expressed in terms of exercise; or more accurately, in terms of lack of exercise. This is the next factor in the explanation of levels of overweight. In short, people who are fat typically don't exercise. Overweight people do move about typically, but ordinarily moving about is not exercising. Exercise defined basically means exerting unusual levels of physical energy. Under this description, walking to the car or moving down the aisle at the grocery store would not constitute exercise.

The next obvious question would be why don't people exercise. People fail to exercise because they choose not to is the obvious answer. A secondary reason, however, and one that likely carries a lot of legitimacy is that people don't exercise because they have little spare time in comparison to the amount of obligations they have. A working person who has children can see literally all of their time filled. But there are always priorities to be made, and not making exercise a priority is a good bet to lead to overweight, and all of the problems that go along with it.