Being overweight or seriously underweight as a teenager curbs life expectancy as much as smoking 10 cigarettes a day, a study suggests.

Swedish researchers followed 46,000 men from the age of 18 for 38 years.

Being obese or smoking more than 10 a day doubled the premature death risk, the British Medical Journal reported.

Being overweight, seriously underweight or smoking 10 or less raised it by 30% - and interestingly the fat non-smoker ran the same risk as the fat smoker.

Being overweight or obese at the age of 18 increases the risk of premature death, regardless of smoking status
Dr Martin Neovius

Those who were underweight - with a Body Mass Index (BMI) of less than 18.5 - had no increased risk of dying early, regardless of whether they smoked or not.

But the team from the Karolinska Institute in Sweden found that those who were seriously underweight - with a BMI of 17 or less - ran the same risk as those who were overweight.

They looked at 45,920 men born between 1949 and 1951 who were military conscripts. In this period as few as 3% of Swedish men were exempt from military service.

Nearly 3,000 of the participants died - with the incidence of death lowest in the normal weight category.

"Compared to normal weight adolescents, being overweight at the age of 18 increased the risk of premature death by just over a third, while being obese more than doubled the risk," the team, led by Dr Martin Neovius, wrote.

And this risk increased regardless of smoking status, they added.

BODY MASS INDEX
Calculated by dividing weight in kilograms by height in metres squared
Normal: 18.5 - 24.9
Overweight: 25 - 29.9
Obese: Above 30

Calculate your BMI

Dr Ian Campbell, of the charity Weight Concern, said the findings were "very interesting".

"When patients who are overweight and smoke ask what they should work on first, we've always said smoking as the wisdom has always been that this poses more health risks - yet this study suggests otherwise."

Betty McBride, of the British Heart Foundation, said: "The government need to bring the same level of sustained focus to tackling the obesity crisis it has previously brought to smoking."

"The number of young people who are overweight and obese is growing. Without tackling this now we risk the next generation growing up with more health problems than their parents."

一項研究證明：作為一個十幾歲的青少年體重超重或嚴重不足平均就如人每天吸10支煙一樣，壽命都會受到限制。

瑞典研究人員密切關注從18歲~38歲的4,600的人。

英國的醫學雜志報道，目前肥胖者或每天吸煙超過10支的人過早死亡的風險增加一倍。

體重超重或嚴重不足者或每天吸10支或少于10支煙的人上升了30 ％ -而有趣的是肥胖非吸煙者與肥胖吸煙者有著相同的早起死亡風險。

這些體重不足-即體重指數（ BMI ）小于18.5，不論他們吸煙與否，都沒有增加早期死亡危險。

但來自瑞典卡羅林斯卡研究院的團體發現，那些體重嚴重不足-即體重指數小于等于17的人-和那些體重超重的人有著相同的過早死亡風險。

他們研究了45,920名生于1949年和1951年之間的應征士兵。在此期間，只有3 ％的瑞典男子被免除兵役。近3000人死亡-是正常體重的最低死亡發生率。

“比起正常體重的青少年，體重超重的18歲青少年過早死亡的風險比其增加超過1/3，同時嚴重肥胖者更是增加了一倍以上危險。 ”我們的研究組博士Neovius 寫道。

他們補充說，不管你是否吸煙，肥胖者的過早死亡風險都會增加。

慈善重量機構的坎貝爾博士說，調查結果“非常有趣” 。

“當肥胖的吸煙病人問他們應首先做些什么，我們總是說，吸煙一直被明確地認為會造成更大的健康風險-然而，這一研究表明并非如此。 ”

英國心臟基金會貝蒂賴德說： “政府必須在關注吸煙對人體帶來過早死亡危機之前同樣地持續關注肥胖問題，以解決肥胖危機。 ”

“青年人中體重超重和嚴重肥胖者的數字不斷增加。如果現在沒有解決這個風險，我們的下一代成長比起他們的父母將會出現更多的健康問題。 ”