Obesity is a high amount of body fat. It leads to a much higher body weight than is normal. This level of body fat can cause serious health issues.

Calories are consumed from food and drinks. They are necessary for physical activity and all basic body functions. A healthy weight is reached by balancing the number of calories you eat and the number of calories you use.

Weight gain occurs when the number of calories eaten is greater than the number of calories used. If this happens regularly, it will lead to obesity. Calorie imbalances happen most often with eating too much food and low levels of physical activity. Less often, it may be caused by a medical condition or medication.