Men who are obese in their early 20s are significantly less likely to reach their middle ages and if they do, they are much more likely to be in seriously ill health, a new study indicates.

It is already known that adults who are obese have an increased risk of developing conditions such as type 2 diabetes and heart disease. However, until now, it was unclear whether being obese in early adulthood increased this risk.

Danish researchers monitored the health of 6,500 men over a 33-year period. All were aged 22 years at the start of the study and 55 years at the end. The participants had originally registered with the Danish Military Board and as part of this, they had undergone a series of psychological and physical tests.

At the age of 22, at least eight in 10 were a normal weight, while one in 10 was overweight. Just 1.5% were obese.

However, the researchers found that among those who were obese at the age of 22, almost 50% had either died or been diagnosed with diabetes, high blood pressure, blood clots in the legs or lungs, stroke or a heart attack by the age of 55.

Overall, they were eight times more likely to develop diabetes compared to their normal weight peers and four times more likely to suffer a venous thromboembolism, which is a potentially fatal blood clot.

They were also at least twice as likely to have suffered a heart attack, to have high blood pressure or to be already dead.

The study also found that every unit increase in body mass index (BMI) corresponded to an increased diabetes rate of 20%, an increased high blood pressure rate of 10% and an increased heart attack rate of 5%.

A healthy BMI is considered 18.5 - 25, while obesity is classified as 30 or more.

The researchers suggested that the rising prevalence of obesity may counteract the fall in deaths from heart disease which many countries are currently achieving.

They also warned that obesity-related morbidity and mortality ‘will, in decades to come, place an unprecedented burden on healthcare systems worldwide'.

Details of these findings are published in the journal, BMJ Open.

To check your BMI, click here