长期以来节食者们一直信誓旦旦地宣称葡萄柚有助减肥。

Now, scientists are beginning to believe them.

如今科学家们也开始相信他们的论断。

A study has found that drinking grapefruit juice when eating fatty food lowers the amount of weight put on by up to a fifth.

一项研究表明食用油脂食物时饮用西柚汁最多可以减少五分之一的增重。

The research also suggested that grapefruit could be as good as prescription drugs at keeping blood sugar levels under control – a key part of managing diabetes.

该研究还指出，在维持血糖处于正常水平方面，葡萄柚可与处方药媲美，而这正是控制糖尿病病发的关键。

The experiments were conducted on mice – but researchers say the results justify studies on humans. Professor Joseph Napoli, of the University of California, Berkeley, said: ‘We see all sorts of scams about nutrition. But these results, based on controlled experiments, warrant further study of the potential health-promoting properties of grapefruit juice.’ 虽然试验对象为老鼠，但研究人员表示结果仍适用于人群。加州大学伯克利分校的约瑟夫·那不勒斯教授说：“我们看过形形色色有关营养品的骗局。但这些控制试验的试验结果已经向我们证明，我们有必要对西柚汁提高人体健康方面的潜力作进一步的研究。”

The Grapefruit Diet, also called the Hollywood Diet, dates back to the 1930s and has a host of celebrity fans including singer Kylie Minogue. It involves having grapefruit or grapefruit juice with every meal while cutting back on calories. 葡萄柚减脂法也称好莱坞减脂法，最早可追溯到20世纪40年代，受到歌手凯莉·米洛等众多好莱坞明星的热烈追捧。那时人们便开始通过每餐食用葡萄柚或饮用西柚汁减低卡路里。

The researchers found that when the mice were fed fatty food for three months, those given grapefruit juice to drink gained up to 18 per cent less weight than those given water. 研究人员发现同样食用了三个月油脂食物的老鼠，与只喝水的老鼠相比，喝过西柚汁的老鼠的增重仅为前者的82%。

They also had lower blood sugar and insulin levels – despite eating the same number of calories and doing the same amount of exercise as the mice who drank water. In fact, grapefruit juice was as good at controlling insulin as the widely used diabetes drug metformin, the journal PLOS ONE reports.

不仅如此，后者的血糖指数和胰岛素指标也相对较低，尽管其卡路里摄入量和运动量与前者没什么区别。据科学公共图书杂志报道，实际上，西柚汁在控制胰岛素方面的作用也不亚于广泛使用的糖尿病药物二甲双胍。

However, the fruit juice only had an effect on weight when the animals ate fatty food.The researchers said they did not know how grapefruit stops the pounds from piling on.

但实验中只有在老鼠食用油脂食物时饮用西柚汁才对减肥有效。研究人员表示他们也不知道为什么葡萄柚能够阻止脂肪的形成。

The British Dietetic Association said the fruit now needs to be thoroughly tested in humans to see if it could help with weight loss and stem the rise of obesity and diabetes.

英国饮食健康协会声称，还需在人体上进行大量试验，以判断葡萄柚是否真的有助于减肥，是否真的能够阻止肥胖和糖尿病的产生。

Spokesman Mariette Abrahams, a dietician, said until then it is too early for people to try grapefruit diets. ‘Grapefruit should be part of a healthy balanced diet, but it shouldn’t be the focus of the diet,’ she said.

反对此做法的代表饮食专家玛丽埃塔·亚伯拉罕曾表示，至少在当时，把食用西柚当作减脂良方还为时过早。“ 食用葡萄柚可以作为健康均衡饮食的一部分，但不能成为节食菜单的主要部分,”玛丽埃塔说道。