New research presented at the European Congress on Obesity (ECO) in Porto, Portugal (17-20 May) suggests that overweight boys may be at greater risk of colon (bowel) cancer when they grow up than their slimmer friends. However, overweight boys who shed the pounds and achieve a healthy weight by young adulthood do not appear to be at increased risk of colon cancer as adults. The findings underline how important it is for children to be a healthy weight.

Previous research shows that overweight children are at higher risk of colon cancer as adults. In this study, Dr Britt Wang Jensen and Associate Professor Jennifer Baker from Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark and colleagues analysed the health records of over 61,000 Danish school boys born between 1939 and 1959, to examine how changes in BMI in childhood and young adulthood are associated with colon cancer risk in adulthood.

The study took educational level into account but not lifestyle factors that might contribute to a person's risk of developing cancer.