DNA does not make overweight inevitable, new study shows
MONDAY, April 5 (HealthDay News) -- Does carrying a gene tied to obesity doom a teenager to becoming obese? Not if that teen stays physically active, a new study shows.
Among genes related to obesity, mutations in the so-called fat mass-and-obesity-associated gene (FTO) appear to be particularly important. In fact, each copy of a mutation in this gene has been tied to an average jump in weight of about 3.3 pounds, the researchers say.
However, an hour of physical activity a day largely negated the gene's effect, the new study found.
"These findings have important public health implications, and indicate that meeting the physical activity recommendations may offset the genetic predisposition to obesity associated with the FTO [gene variant] in adolescents," said lead researcher Jonatan R. Ruiz, a scientist in physical activity and fitness epidemiology at the Karolinska Institute in Huddinge, Sweden.
The report is published in the April issue of the Archives of Pediatrics & Adolescent Medicine.
For the study, Ruiz's team collected data on 752 teens who took part in the Healthy Lifestyles in Europe by Nutrition in Adolescence Cross-Sectional Study, which was conducted in 10 European countries between October 2006 and December 2007.
Among these teens, 37 percent did not have FTO mutations, 47 percent had one copy and 16 percent had two copies. Copies of the mutation were linked with higher body mass index (BMI). BMI is a measure of weight divided by height. Statistically, a BMI of 25 is considered the threshold for overweight while a BMI of 30 is the threshold for obesity.
Copies of the gene mutation were also linked with a higher percentage of body fat and a larger waist.
For teens who got at least an hour of physical activity each day, the effect of the obesity-linked gene mutation on weight was mu
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