Being overweight may cause higher blood pressure and thicken heart muscle, setting the stage for heart disease later in life, a study has found.
The research, published in the journal Circulation, is the first to explore if higher body mass index (BMI) - a weight-for-height index - results in adverse effects on the cardiovascular system in young adults.
"Our results support efforts to reduce body mass index to within a normal, healthy range from a young age to prevent later heart disease," said Kaitlin H Wade from the University of Bristol Medical School in the UK.
Researchers used data on several thousand healthy 17-year-olds and 21-year-olds participating in an ongoing study since birth in Bristol, UK.
The findings suggest that higher BMI caused higher systolic (top number) and diastolic (bottom number) blood pressure.
It also caused enlargement of the left ventricle, the heart's main pumping chamber, the researchers said.
"Thickening of vessel walls is widely considered to be the first sign of atherosclerosis, a disease in which fatty plaques build up within the arteries and lead to heart disease.
"However, our findings suggest that higher BMIs cause changes in the heart structure of the young that may precede changes in blood vessels," Wade said.
Two of the analyses used in the study (Mendelian randomisation and recall-by-genotype) take advantage of the properties of genetic variation.
Recall-by-genotype is novel and exploits the random allocation of genes at conception.