However, he said: ‘These findings demonstrate that the effect of obesity is powerful, even in the young, and that lifestyle and nutritional intake starting in childhood have major repercussions throughout all stages of life.'
Dr Dandona said in addition to the reproductive consequences, the absence or low levels of testosterone that were found also will increase the tendency toward abdominal fat and reduced muscle, leading to insulin resistance which contributes to diabetes.
He added: ‘The good news is that we know that testosterone levels do return to normal in obese adult males who undergo gastric bypass surgery.
‘It's possible that levels also will return to normal through weight loss as a result of lifestyle change, although this needs to be confirmed by larger studies.'
The researchers now intend to study whether or not weight loss accomplished either through lifestyle changes or through pharmacological intervention will restore testosterone levels in obese teenage boys.
The paper was published online in the journal Clinical Endocrinology.
