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."

一项研究证明：作为一个十几岁的青少年体重超重或严重不足平均就如人每天吸10支烟一样，寿命都会受到限制。

瑞典研究人员密切关注从18岁~38岁的4,600的人。

英国的医学杂志报道，目前肥胖者或每天吸烟超过10支的人过早死亡的风险增加一倍。

体重超重或严重不足者或每天吸10支或少于10支烟的人上升了30 ％ -而有趣的是肥胖非吸烟者与肥胖吸烟者有着相同的早起死亡风险。

这些体重不足-即体重指数（ BMI ）小于18.5，不论他们吸烟与否，都没有增加早期死亡危险。

但来自瑞典卡罗林斯卡研究院的团体发现，那些体重严重不足-即体重指数小于等于17的人-和那些体重超重的人有着相同的过早死亡风险。

他们研究了45,920名生于1949年和1951年之间的应征士兵。在此期间，只有3 ％的瑞典男子被免除兵役。近3000人死亡-是正常体重的最低死亡发生率。

“比起正常体重的青少年，体重超重的18岁青少年过早死亡的风险比其增加超过1/3，同时严重肥胖者更是增加了一倍以上危险。 ”我们的研究组博士Neovius 写道。

他们补充说，不管你是否吸烟，肥胖者的过早死亡风险都会增加。

慈善重量机构的坎贝尔博士说，调查结果“非常有趣” 。

“当肥胖的吸烟病人问他们应首先做些什么，我们总是说，吸烟一直被明确地认为会造成更大的健康风险-然而，这一研究表明并非如此。 ”

英国心脏基金会贝蒂赖德说： “政府必须在关注吸烟对人体带来过早死亡危机之前同样地持续关注肥胖问题，以解决肥胖危机。 ”

“青年人中体重超重和严重肥胖者的数字不断增加。如果现在没有解决这个风险，我们的下一代成长比起他们的父母将会出现更多的健康问题。 ”