Hereditary Risk: High
Most Vulnerable: Children whose parents are significantly overweight. If one parent is obese, a child's risk of having weight problems is 40 percent, and it's 70 percent if both parents are obese. "In most cases, however, if a child has a healthy diet and gets regular physical activity, he can overcome a genetic susceptibility to being overweight," says Dr. Mendelsohn. Childhood obesity is nothing to take lightly. It can increase the risk of diabetes, early heart disease, asthma, and some cancers.
Best Defenses: Be a good role model; kids learn their eating and exercise habits by watching their parents and siblings. Doctors don't recommend putting children on restrictive low-fat diets, but it's important to limit sugary sodas and snacks, offer a variety of nutrient-rich foods, cut back on television time (no more than two hours per day), and make fitness a family priority. After age 2, your child's body mass index should be calculated by his pediatrician at every checkup so that weight problems can be spotted early.