The cause of obesity is not the same for each individual. Body weight is the result of many factors, including energy balance (calories consumed vs. calories used), heredity, metabolism, eating and social habits and psychological factors.

Energy Balance

Your body needs calories to function. When you consume more than you need, your body stores the energy for future use in the form of fat. A lack of physical activity also contributes to an energy imbalance. The prevalence of time- and labor-saving devices, such as cars, elevators and the like, along with an increase in sedentary jobs has decreased the overall amount of physical activity that Americans get.

Heredity

While heredity can play a role in weight gain, it is not the leading culpable factor. Too little physical activity and excess calorie consumption often accompany genetic predisposition in contributing to excess weight.

Metabolism

Metabolism is a calorie-burning process by which the body breaks down substances so that it can extract what it needs to live. The rate of metabolism varies among individuals and can be affected by a number of  diseases. It is best to consult your physician about them.

Eating and Social Habits

America offers a plethora of food choices and in abundant amounts. Food options and availability are ever-increasing and the types of foods offered are often high in calories, fat and sugar. Nutritional information can often be deceptive, masking high calories with a "low-fat" label, for instance. Social occasions often revolve around foods and can contribute to weight gain.

Psychological Factors

Psychological factors can influence eating habits and physical activity. Negative emotions can lead to overeating and a lack of exercise, which in turn can lead to more negative emotions, triggering a vicious cycle.

Obesity is a chronic disease. The good news is that treatment exists.