The prevalence of childhood obesity among African Americans, Mexican Americans, and Native Americans exceeds that of other ethnic groups. In fact, the Centers for Disease Control reported that in the year 2000, 19 percent of non-Hispanic Black children and 20 percent of Mexican American children were obese compared with 11 percent of non-Hispanic White children.
The increase since 1980 is particularly evident among non-Hispanic Black and Mexican American adolescents. And the relationship between race/ethnicity and childhood obesity may result from a number of underlying causes, including less healthy eating patterns (e.g., eating fewer fruits and vegetables, more saturated fats), engaging in less physical activity, and cultural attitudes about body weight.
There is also an abundance of evidence that supports genetic susceptibility as another important risk factor for obesity. Evidence from twin, adoption and family studies strongly suggests that biological relatives exhibit similarities in maintenance of body weight, and heredity contributes between 5 and 40 percent of the risk for obesity. Other studies indicate that 50-70 percent of a person's body mass index (BMI) is determined by genetic influences and that there is a 75 percent chance that a child will be overweight if both parents are obese, and a 25-50 percent chance, if just one parent is obese.
Although this relationship is well established, the role of genetics in obesity is complex, and simply having a genetic predisposition to obesity does not guarantee that an individual will be overweight. Increases in the incidence and prevalence rates of obesity in the United States are likely due to behavioral or environmental factors, which have interacted with genes, and not the effects of genetics alone.
According to the Mayo Clinic, there are a number of different medical challenges that result from childhood obesity.
* Metabolic syndrome. Metabolic syndrome isn't a disease itself, but a cluster of conditions that can put a child at risk for developing heart disease, diabetes or other health problems. This cluster of conditions includes high blood pressure, high blood sugar, high cholesterol and excess abdominal fat.
* Type 2 diabetes. Type 2 diabetes is a chronic condition that affects the way a child's body metabolizes sugar (glucose). Type 2 diabetes is caused in part by a poor diet, and can often be reversed by eating healthier foods and exercising.
* High cholesterol and high blood pressure. A child can develop high blood pressure or high cholesterol if he or she eats a poor diet. These factors can contribute to the buildup of plaque in the arteries, which can cause them to narrow and harden, and thus lead to a heart attack or stroke later in life.
* Asthma and other breathing problems. The extra weight on a child's body can cause problems with the development and health of the child's lungs, leading to asthma or other breathing problems.
* Sleep disorders. Sleep apnea, a condition in which a child may snore or have abnormal breathing during sleep, can be a complication of childhood obesity.
* Early puberty or menstruation. Being obese can create hormone imbalances for a child. These imbalances can cause puberty to start earlier than expected in both boys and girls.