The spotlight has been on childhood obesity of late, with two corresponding studies linking obesity with both genetics and lifestyle.

An international collaboration of researchers recently concluded that, contrary to common opinion, childhood obesity has a genetic component.

The team used genome-wide association techniques to show that there are many genetic variants with adult obesity which are also present in children.

Additionally, the researchers unveiled two new genetic variants which had not been previously associated with obesity. Struan Grant of the Children's Hospital of Philadelphia told MedPage Today: "There is indeed a genetic signature of childhood obesity.

"It's not purely lifestyle."

However, the study noted that human genetics had not changed in the past few decades, whereas the level of obese children had. This suggests that even though genetics may have an impact on childhood obesity, it is likely to be something that occurs when coupled with a poor diet and unhealthy lifestyle.

This is where research published in the American Journal of Preventive Medicine comes into play. A new study has attempted to find how many calories it takes to reach childhood obesity prevention goals set by the federal government in America. These goals were set as a response to research that found more than one in five young people will be obese by 2020 if eating habits are maintained.

The study found that, in order for the nation to achieve goals set by the federal government for reducing obesity rates by 2020, children in the United States would need to eliminate an average of 64 excess calories per day. The results have been published in the American Journal of Preventive Medicine.

Y. Claire Wang, MD, ScD, assistant professor of Health Policy and Management at Columbia University's Mailman School of Public Health and lead author of the study, said: "64 calories may not sound like much individually, but it's quite a consequential number at the population level, and children at greatest risk for obesity face an even larger barrier.

"Closing this gap between how many calories young people are consuming and how many they are expending will take substantial, comprehensive efforts."