Family history ; psychological factors , and (1) diet all play a role in childhood obesity . Children whose parents or other family members are (2) overweight or obese are more likely to follow suit . But the main (3) cause of childhood obesity is a combination of eating too much and exercising too little .

A poor (4) lifestyle containing high levels of fat or sugar and few nutrients can cause kids to gain weight quickly . Fast food , candy , and soft drinks are common culprits . The U.S. Department of Healthy & Human Services ( HHS ) reports that 32 percent of adolescent girls and 52 percent of adolescent boys in the United States drink 24 ounces of soda - or mor - perday .

Convenience foods , such as frozen dinners , salty snacks , and canned pastas , can also (5) contribute to unhealthy weight gain . Some children become obese because their parents don't know how to choose or prepare healthy foods . Other families may not be able to easily afford fresh fruits , vegetables , and meats .

Not enough (6) physical activity can be another cause of childhood obesity . People of all ages tend to gain weight when they're less active . Exercise burns (7) calories and helps you maintain a healthy weight . Children who aren't encouraged to be active may be less likely to burn extra calories through sports , time on the playground , or other forms of physical activity .

Psychological issues may also lead to obesity in some children . Kids and teens who are bored . stressed , or depressed may eat (8) more to cope with negative emotions .