Young men who are obese in their early 20s are significantly more likely to develop serious health problems by the time they reach middle age, according to research published in BMJ Open.

While previous studies have focussed on the impact of obesity in adulthood, this research makes clearer the connection between poor health outcomes and obesity in early adulthood.

The authors tracked the health of 6,500 22-year-old men, all born in 1955, up to the age of 55. All men had registered with the Military Board for a fitness test to gauge their suitability for military service.

The research found obese participants were eight times as likely as their normal weight peers to get diabetes, four times as likely to potentially fatal blood clots, and more than twice as likely to develop high blood pressure, have a heart attack or to have died.

Every unit increase in BMI corresponded to an increased heart attack rate of 5 per cent and increased diabetes rate of 20 per cent.

The study's authors said: "Thus, obesity morbidity and mortality will, in decades to come, place an unprecedented burden on healthcare systems worldwide."