The reasons for obesity are not clear. Although obesity occurs when the number of calories consumed is greater than the amount of energy spent, not all obese people overeat. They may have a slower rate of metabolism, the amount of energy needed to maintain the basic body functions when at rest. Obese people also use up fewer calories because it's harder for them to be physically active. Emotional problems, such as depression, anger, and anxiety can occasionally be a cause.
Emotional problems can contribute to the obesity or can result from it.
Heredity is a contributing factor. Children who have obese parents are 10 times more likely to become obese adults than children who have parents of normal weight. There is also an environmental factor because unhealthy eating habits may be reinforced in families. A few obese people have an imbalance of hormones. Obesity is a more serious condition than being overweight because there is a greater risk for serious illnesses.