FRIDAY, Dec. 7, 2001 (HealthDayNews) -- If you were thin as a kid and put on extra weight as an adult, you're more at risk from diseases linked to obesity than if you were fat as a kid and grew up to be fat, a new study says.
With obesity in children at epidemic levels, researchers are concerned that being fat as a kid could mean heart disease, diabetes, osteoarthritis and some types of cancer as a grownup. But no one is sure if these risks are a result of being fat in childhood or adding pounds in adulthood.
There is less risk if you were overweight as a child, says lead study author Dr. Charlotte Wright, a senior lecturer in community child health at the University of Glasgow, in Scotland.
"What we found, basically, is that body fatness in adulthood was, as you would expect, related to a wide array of risks and disease, such as heart disease, diabetes and stroke," Wright says. "But while you would expect that how fat you were as a child would lead you to increased risk for disease in adulthood, we basically found very little association. In fact, we found the opposite of what we expected -- that being fat as a child had a slightly inverse risk for disease, while being thin as a child and getting fat as an adult increased your risk for disease."
To check whether childhood obesity correlated with adult obesity and risk for disease, Wright and her colleagues used information from a study that has followed for 50 years everyone born in the English city of Newcastle in 1947.
The researchers compared body mass index (BMI) measurements of 412 individuals taken at ages 9 and 13 with both BMI measurements and actual percentages of body fat at age 50. They then looked at such disease indicators as blood pressure, artery thickness, cholesterol and triglyceride concentrations, and blood sugars.
BMI at the age 9 was significantly linked to BMI at age 50, but not with the percentage of body fat, Wright says. And being fat at age 13 also was associated with being overweight at age 50. "What we also found, however, was very little association with disease markers -- being fat as a child was actually associated with a lower risk for triglycerides and total cholesterol," she says. "And the interesting thing was that being thin as a child didn't protect you from being fat as an adult, and, on the whole, those who had been thin as a child and got fat when an adult were at an increased risk for disease."
The findings appear in the Dec. 1 issue of the British Medical Journal.
Obesity rates in the United States are rising steadily, reports the National Center for Health Statistics (NCHS). The percentage of children and adolescents defined as overweight has more than doubled since the early 1970s, and about 13 percent of U.S. kids and teen-agers are now seriously overweight, says the NCHS. Currently, more than half of all U.S. adults are considered overweight, defined as a BMI of 25 or more. The incidence of overweight among U.S. adults increased 61 percent from 1991 to 2000 alone.
While the study is interesting, the fact that researchers compared childhood BMI to the percentage of adult body fat using a process called bioelectrical impedance -- a test that determines how much lean muscle, fat, bones and water you have in your body -- may be problematic, says national obesity expert James Hill, professor of pediatrics and director of the Center for Human Nutrition at the University of Colorado Health Sciences Center, in Denver.
"The primary concern is that the measure of body fat they use -- bioelectrical impedance -- is not thought by many experts to have a high degree of accuracy," Hill says.
Regardless of the study, don't think that being fat as a child is something to take lightly, Hill says.
"I think we cannot use this study to suggest that we should not try to prevent weight gain in children," he says. "Many other studies show strong tracking of obesity in childhood through adulthood. Regardless of weight in childhood, most adults are becoming obese. The real message here is that we need prevention of weight gain for all ages."
What To Do
To learn more about the implications of childhood obesity, see the American Academy of Family Physicians. And if you're looking for information on being overweight as an adult, check the National Institute of Diabetes & Digestive & Kidney Diseases.
What's your BMI? Find out with a calculator at the Mayo Clinic Web site, which also explains the math.
