It's All in the Genes: Obesity Can Be Inherited From Parents

A child born and raised by obese parents is more likely to grow up as obese too compared to those who were raised by thin parents, a new study from Sussex revealed.

The study, published in the journal Economics and Human Biology, showed that more than half of the body mass index of most obese children were determined by their genes and family environment, in other words, their obesity were inherited.

"This shows that the children of obese parents are much more likely to be obese themselves when they grow up," said Peter Dolton, a professor from University of Sussex and lead author of the study, in a press release. "The parental effect is more than double for the most obese children what it is for the thinnest children."

For the study, the researchers analyzed the data on heights and weights of 100,000 children and their parents across six different countries: U.S., U.K., Spain, China, Mexico, China and Indonesia. The six countries have very diverse patterns of nutrition and obesity. The U.S. is considered to be one of the most obese populations in the world. On the other hand, China and Indonesia are two of the least obese populations.

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The researchers found that about 35 to 40 percent of a child's body mass index is inherited from their parents. The intergenerational transmission of BMI is approximately constant at around 0.2 percent. This suggests that 20 percent of a child's BMI were influenced by the mother and 20 percent were due to the father.

The transmission of BMI is more apparent in most obese children; around 55 to 60 percent of their BMI was inherited from their parents. This suggests that children born and raised by obese parents have over 50 percent chance of becoming obese.

Despite the huge difference in the economic development, degree of industrialization or type of economy between the six countries, the pattern of results remain remarkably consistent.