London, Nov 11 (IANS): Boys with excessive weight gain during puberty are at increased risk of death due to heart disease later in life, a study reveals.

There is no corresponding risk among boys being overweight when younger and who have normal weight during adolescence.

The study included over 37,600 men and the change in body mass index (BMI) during puberty was calculated using BMI values at eight and 20 years of age.

The study evaluated the contribution of BMI during the two distinct developmental periods -- childhood and puberty for cardiovascular mortality in adult men.

Increased cardiovascular mortality was seen in boys with a large increase in BMI during puberty, while there was no increased risk for those who were overweight prior to puberty but whose BMI normalised during puberty. Thus, excessive BMI increase during puberty seems unhealthy.

"In this study, we show that a large increase in BMI during puberty is particularly important, while high BMI at age eight is not linked to increased risk of cardiovascular death," said Jenny Kindblom, Associate Professor at the University of Gothenburg, Sweden.

According to the present study, the increased risks occur in the group of boys whose BMI increased by more than seven BMI units during puberty. Within this group, the risk of death due to cardiovascular disease later in life increases by 22 per cent for every extra BMI unit.

The study is being published in The Lancet Diabetes & Endocrinology.