Obesity Health Center
Some people are born with genetic factors that cause them to be obese, but in general, the main causes of obesity are overeating and inactivity.
Simply put, consuming more calories than the body can burn results in weight gain. This is because the body will store excess calories as body fat. Exercise increases the number of calories the body burns and, therefore, can aid in weight loss or obesity prevention.
Other causes of and contributing factors to obesity include getting too little sleep and certain medications. Both insomnia and some medications can cause hormonal or chemical changes that cause increased appetite or cravings for unhealthy foods.