It is the question on every dieter's lips... when will people notice the pounds dropping off?

几乎每个节食者都有这样一个疑问：什么时候才能让别人发现自己瘦下来了呢？

A host of diets promise to help transform the body, while countless studies reinforce the need to combine healthy eating with regular exercise.

一系列饮食可以帮助人们改造身体，同时，无数研究也证实，健康饮食需与规律锻炼相结合。

致减肥的你：如何获得异性的青睐？

But now, a new piece of research has taken the weight-loss conundrum one step further.

但如今，一项新研究为减肥难题带来进一步发展的空间。

And its conclusion is seemingly simple, you need to shed eight to nine pounds, just over half a stone, before your friends and family will notice it in your face.

而且这个结论似乎颇为简单，你需要减掉8-10磅，即半英石（英国质量单位）多体重，然后亲友才能看出你瘦了，因为脸瘦了。

However, in order to appear more attractive to the opposite sex, it is necessary to double that weight loss, and shed 15 pounds - just over one stone.

然而，如果你想更多吸引异性目光的话，就需要减掉以上体重的两倍之多，即减去15磅（一英石多体重）。

Researchers at the University of Toronto revealed in order for anyone to look more attractive, it is important they lose weight from their face.

多伦多大学的研究员发现，如想让自己变得更迷人，瘦脸很重要。

For even if our waists appear slimmer just losing a few pounds is not enough for others to notice.

甚至，腰瘦了几磅，看起来细了都不足以被他人发现。

It's not until the weight loss affects a person's face that they are likely to be inundated with compliments.

除非减肥效果在脸上得以体现，否则你很难收到别人夸你瘦了之类的赞美之词。

Dr Nicholas Rule of the University of Toronto Department of Psychology said: ‘Women and men of average height need to gain or lose about three and a half and four kilograms, or about eight or nine pounds, respectively, for anyone to see it in their face.

多伦多大学心理学系的尼古拉斯教授称：“相同身高的女性和男性，如果他们想让别人看出自己脸是胖还是瘦，都需要分别增重或减轻3.5和4公斤，或者 8和9磅。”

‘But they need to lose about twice as much for anyone to find them more attractive.’

Researchers found that facial adiposity – which is the perception of weight in the face – is an accurate indicator of a person’s body mass index (BMI).

“但如果他们希望别人觉得自己更有魅力的话，则需要减掉以上体重的两倍之多。”研究员发现，面部脂肪（通过面部感知重量）可以准确的反映一个人的身体质量指数（BMI）。

It is also a robust indicator of a person’s health, since higher facial adiposity is associated with a variety of health problems, from a compromised immune system to poor cardiovascular health.

它还能反映一个人是否健康，是否体能下降。因为过多的面部脂肪可能涉及一系列健康问题，从免疫系统恶化到心血管功能紊乱。

The study sought to determine at what point a change in the perception of facial adiposity occurs.

该项研究旨在解决人们何时会察觉到面部脂肪。

They created a collection of male and female faces between 20 and 40 years old, in which all of the subjects had neutral expressions, their hair pulled back and no facial adornments.

他们将一群20-40岁的男女集合起来拍照，并规定所有人都面无表情，头发梳至脑后，面部无任何修饰。

They also altered each image to create a sequence of photos showing a range of weights on a gradually increasing scale.

他们还按照从轻到重的程度，调整照片来创建序列。

study participants were asked to compare randomly drawn pairs of faces from each sequence and identify the heavier-looking one.

研究参与者被要求从每个序列中随机抽取一对面部照片进行对比，并选出一个看起来比较重的。

BMI is calculated as a person’s weight in kilograms divided by the square of the person’s height in meters.

身体质量指数计算方式为：一个人的体重（公斤）除以其身高的平方（米）。

Through their trials, researchers determined that a body mass index change of approximately 1.33 kg/m2 is required for a difference in weight to be noticeable.

通过试验研究员认为，一个人的身体质量指数变化约为1.33kg/m2时，才可以让别人发现自己瘦了。

The study also looked at the threshold at which a person’s facial adiposity led people to find them more attractive.

这项研究还解决了一项问题，那就是面部脂肪需要达到多少才能够更加吸引别人。

Researchers concluded that women need to have a BMI of 2.38 kg/m2 to appear more attractive, while men need to lower their body mass index by 2.59 kg/m2.

研究发现，女性的身体质量指数需达到2.38 kg/m2才会看起来更加迷人，而男性则需要将身体质量指数降至2.59 kg/m2。

That translates to approximately 14 and 18 pounds (or 6.3 and 8.2 kilograms) respectively for women and men of average height.

这意味着，相同身高的男性女性需要分别减掉14和18磅（或6.3和8.2公斤）。

‘The difference between the groups suggest women’s facial attractiveness may be more sensitive to changes in weight,’ Dr Rule said.

“各组之间的差异表明，女性的面部吸引力对于体重变化来说更为敏感。”鲁尔教授说。

‘This just means women attempting to lose weight need to shed slightly fewer pounds than men for people to find them more attractive.’

“这就意味着，想减肥的女性必须比男性减掉更多的重量才能吸引更多他人的目光。”