According to statistics, a child is 40% more likely to become obese if one of his parents is morbidly overweight; he is 80% more likely to struggle with obesity if both parents are obese. Children who become obese early on are subject to a plethora of lifelong health issues.
In addition to some of the obvious reasons this occurs, researchers have found a genetic anomaly they believe is responsible for some cases of severe obesity in children. A study of 300 obese children conducted by the University of Cambridge looked at the complete genomes of the children involved. Specifically, scientists looked at deletions and duplications of DNA, which they believe is the cause of certain genetic diseases and disorders.
These genetic variations are known as copy number variants, which researchers have linked to other disorders, such as autism.
After scanning the entire genomes of all of the children, they found a commonality: many of them were missing part of a gene in chromosome 16. This genetic absence, the researchers discovered, causes a strong desire to eat.
Identical Twin Studies
The Cambridge study lends credence to an earlier twin study conducted in 2008; that study tried to determine how much the effects of environment and genetics have on obesity risk. Twin studies are often conducted in an effort to discover which traits are determined by nature rather than nurture. Identical twins share all of their genes, while fraternal twins share about half of them.
Researchers conducting the twin study concluded that ¾ of obesity risk is due to genetics, while only ¼ is attributable to environment (American Journal of Clinical Nutrition).
This type of research is important because according to the CDC, the number of obese preschoolers and teenagers has doubled over the last 30 years, while obesity in children ages 6-11 has tripled during the same time period.
Moreover, parents of obese children are often accused, either overtly or covertly, of abuse in the form of overfeeding. As a result of the Cambridge study, some children who were actually removed out of their homes and put into foster care have been returned to their families of origin.
Environment Still a Factor
All of this does not mean that environment is irrelevant when it comes to childhood obesity. However, it does show that some children do not have as much leeway as other kids do when it comes to being overweight; therefore adjustments need to be made with regards to what these children eat and how much exercise they get.