A British study reveals that obesity in children is not only because of lack of exercise and wrong dietary habits, but there is a strong genetic influence amongst other factors that lead to childhood obesity.
The study conducted by researchers from University College London published in the American Journal of Clinical Nutrition.
Body mass index (BMI) has been shown to be highly heritable, but most studies were carried out in cohorts born before the onset of the “obesity epidemic.” Researchers aimed to quantify genetic and environmental influences on BMI and central adiposity in children growing up during a time of dramatic rises in pediatric obesity or childhood obesity.
Researchers carried out analyses of BMI and waist circumference (WC) in a UK sample of 5092 twin pairs aged 8?11 year.
The analysis confirmed substantial heritability for BMI and WC (77% for both). It showed that, although the genetic influence on WC was largely common to BMI (60%), there was also a significant independent genetic effect (40%). For both BMI and WC, there was a very modest shared-environment effect, and the remaining environmental variance was unshared.
Genetic influences on BMI and abdominal adiposity are high in children born since the onset of the pediatric obesity epidemic. Most of the genetic effect on abdominal adiposity is common to BMI, but 40% is attributable to independent genetic influences. Environmental effects are small and are divided approximately equally between shared and nonshared effects.
Researchers concluded “targeting the family may be vital for obesity prevention in the earliest years, but longer-term weight control will require a combination of individual engagement and society-wide efforts to modify the environment, especially for children at high genetic risk”.
Evidence for a strong genetic influence on childhood adiposity despite the force of the obesogenic environment by Jane Wardle, Susan Carnell, Claire MA Haworth and Robert Plomin.
Source: American Journal of Clinical Nutrition, USA