Children become overweight for a variety of reasons. The most common causes are genetic factors, lack of physical activity, unhealthy eating patterns, or a combination of these factors. In rare cases, a medical problem, such as an endocrine disorder, may cause a child to become overweight. Your physician can perform a careful physical exam and some blood tests, if necessary, to rule out this type of problem.

Genetic Factors

Children whose parents or brothers or sisters are overweight may be at an increased risk of becoming overweight themselves. Although weight problems run in families, not all children with a family history of obesity will be overweight. Genetic factors play a role in increasing the likelihood that a child will be overweight, but shared family behaviors such as eating and activity habits also influence body weight.

Lifestyle

A child's total diet and his or her activity level both play an important role in determining a child's weight. The increasing popularity of television and computer and video games contributes to children's inactive lifestyles. The average American child spends approximately 24 hours each week watching television-time that could be spent in some sort of physical activity.