Older sisters often moan that their younger siblings have all the luck. But it seems they really do have something to complain about – for research has found that younger sisters are more likely to be slimmer than firstborn girls.
當姐姐的總是抱怨妹妹運氣太好。現在看來，她們的抱怨也不是無中生有。有研究發現，比起家里排行最大的姐姐，妹妹們更有可能身材苗條。

The study – the largest of its kind – suggests that birth order may play an important role in determining weight. And the researchers warned that firstborns could be at risk of other health problems too.
這是該領域內規模最大的一次研究，研究結果表明，出生順序或許很大程度上決定了體重。研究員同時警告稱，長子長女還有可能出現其他健康問題。

The scientists looked at data on the health of 13,400 pairs of sisters and found that firstborn women were, on average, 29 per cent more likely to be overweight and 40 per cent more likely to be obese than second-born sisters. The findings back up similar research on men that found firstborn males were more likely to be overweight than younger brothers.
科學家們比對了13400對姐妹的健康數據，結果發現，平均而言，與排行老二的妹妹相比，排行老大的姐姐超重的可能性高29%，肥胖的可能性高40%。這一發現與另一項針對男性的相似研究的結果相符，后者研究發現，比起弟弟，排行老大的哥哥超重的可能性更大。

The latest research examined data from pregnant Swedish women, gathered between 1991 and 2009. Weighed when they were between ten and 12 weeks pregnant, firstborn women were 1lb 4oz heavier on average than second-born sisters. This meant their body mass index (BMI) was 2.4 per cent higher. Firstborn sisters were only negligibly taller, measuring an additional 1.2mm on average.
最新研究比對了1991年至2009年間收集的瑞典孕婦的體重數據。研究員們分別在孕婦懷孕10周和12周時測量了她們的體重，發現排行老大的姐姐比排行老二的妹妹平均重1磅4盎司（0.57千克）。這表明，姐姐的身體質量指數（BMI）比妹妹高了2.4%。而姐姐平均身高只比妹妹高了1.2毫米，可以忽略不計。

The researchers also noted a considerable increase in average weight over the 18-year period, rising by four ounces per year.
研究員們也注意到，18年間，她們的平均體重有顯著的增長，每年增重4盎司（約0.11千克）。

The experts, from the University of Auckland in New Zealand and Uppsala University in Sweden, said it was unclear why older sisters seemed to be heavier. But they said the findings could explain why obesity figures appear to be soaring.
新西蘭奧克蘭大學（University of Auckland）和瑞典烏普薩拉大學（Uppsala University）的專家表示，姐姐更重的原因尚不清楚，但這一發現可以解釋為何超重者的人數在飆升。

The scientists also said there is mounting evidence that firstborns are more at risk of health problems such as diabetes and high blood pressure in later life than their siblings. But the underlying causes for these differences are far from clear, they added.
科學家們還說，越來越多的證據表明，在日后的生活中，長子長女比他們的弟弟妹妹更容易受到健康問題的困擾，例如糖尿病、高血糖等。不過還表示，造成這些差異的潛在原因還不得而知。

Vocabulary
negligibly: 極小地，可以忽略不計地
epidemiology: 流行病學

英文來源：每日郵報
譯者：zsxfybs
審校：劉秀紅
編輯：許晶晶