Is the increase in teenage obesity due to lack of calorie burning?

A new study has concluded that the increase in teenage obesity is due to the number of calories that they burn dropping dramatically in puberty. The 12-year-long study was led by the University of Exeter Medical School and is published in the International Journal of Obesity. Puberty is a time when calorie burning is expected to increase due to growth spurts; however this study found that 15 year olds burn a quarter fewer calories at rest than they do when they are 10. The study also found that the amount of physical activity that teenagers undertake also drops during the onset of puberty.
The team analysed data from 350 school children at 6-monthly intervals. Blood samples were also taken to assess metabolic health as well as measurements of size. The children were placed in rooms that measured the amount of oxygen that was consumed at rest, this was then used to calculate the number of calories that were burnt. At the moment the team can only speculate as to the reasons that there was a drop in calories used, with one explanation being a possible evolutionary change where calories are conserved for growth. The team are hoping to continue their research in order to provide further answers to this surprising conclusion.