Obesity isn’t all about the food you eat or the amount of physical activity you do, genetics also play a role. Some children are at a greater risk of being obese simply because of their genetic make up. If a child’s parents or immediate family tend to gain weight easily, a child may have the same physical genetic disposition for weight gain. However, even genetics cannot cause obesity alone. To become obese, children must eat more calories than they need for growth and daily energy.