A new study has shown that children who are overweight before the age of 12 are more likely to be overweight by the time they reach age 12. The study included 1000 US children born in 1991—around the time the "obesity epidemic" started gaining attention. Researchers took measurements of the children at 7 different times in their childhood: at 2 years, at 3 years, at 4½ years, at 7 years, at 9 years, at 11 years, and at age 12.

They found that the more times a child was recorded as being medically overweight, the more likely he or she was to be overweight at age 12. One overweight measurement meant the child was 25 times more likely to be overweight; 3 overweight measurements made the child 374 times more likely to be overweight.

Philip K. Nader, MD, of the University of California, San Diego School of Medicine, said, "These results suggest that any time a child reaches the 85th percentile for BMI [body mass index] may be an appropriate time for an intervention." Percentiles and their corresponding weight levels are listed in the following table from the Centers for Disease Control and Prevention:

The 95th percentile:

• Corresponds to a BMI of 30, which is the marker for obesity in adults. The 85th percentile corresponds to the overweight reference point for adults, which is a BMI of 25.
• Is recommended as a marker for children and adolescents to have an in-depth medical assessment
• Identifies children who are very likely to have obesity persist into adulthood
• Is associated with elevated blood pressure and lipids in older adolescents and increases their risk of diseases
• Is a criterion for more aggressive treatment
• Is a criterion in clinical research trials of childhood-obesity treatments

Risk Factors for Overweight/Obese Children and Adolescents

• Cardiovascular disease*
• High cholesterol
• Elevated insulin levels
• Elevated blood pressure during childhood
• Type 2 diabetes
• Sleep apnea (not breathing for at least 10 seconds during sleep)
• Social consequences including poor self-esteem and social discrimination, which can lead to depression

*One study showed that approximately 60% of overweight children had at least one cardiovascular risk factor, such as high cholesterol or high blood pressure; in comparison, only 10% of children with healthy weight had at least one risk factor. Additionally, 25% of overweight children had 2 or more risk factors.

Ms. Farley is a freelance medical writer based in Wakefield, RI.