For decades, diet gurus have advised slimmers to simply 'eat less' but while that mantra seems easy, it turns out that it's harder than it sounds.

长久以来，减肥达人总是告诫那些想减肥的人，一定要少吃点。这看起来很简单，其实却非常困难。

However, Emma Brown, a nutritionist says that broadly one portion counts as 120g of steak, one biscuit and just half a scone.

不过，一位名叫艾玛·布朗的营养学家却告诉大家，其实只要每次只吃一份科学份额的食物就刚刚好，这一份食物可以是120克的牛排，一片饼干，或者半个英式茶饼。

Here she explains how much of each food group you should really be eating each day.

她告诉我们每天每一种食物应该食用的分量。参见下表：

A portion of red meat is 120g and has 162 calories and 5.4g of fat. Although small amounts of protein regularly throughout the day are good for you, try not to have red meat too often.

一份科学份额的红肉重120克，含有162卡的热量，5,4克脂肪。虽然吃小份额的红肉能够为你提供日常所需的蛋白质，不过最好不要经常吃红肉。

A portion of fish is 125g which contains 271 calories and 18.8g of fat. A healthy diet should include at least two portions of fish a week, including one of oily fish.

一份鱼肉有125克，含有271卡热量，18.8克脂肪。健康饮食应保证每周至少吃两个份额的鱼肉，包括一份油炸鱼肉。

A portion of potatoes should be 235g with 172 calories per portion, Emma also advised eating the skin for extra nutrients.

一份额重235克，有172卡热量。艾玛还建议大家吃土豆的时候带皮一起吃，可以额外补充维生素哦。

Vegetables should be in portions of 80g, there's 27 calories in these carrots and they count as one of your five a day.

蔬菜的份额应为80克，一份额的胡萝卜包含27卡热量，每天应该吃5份额的蔬菜。

Fruit is also 80g per portion, with 28 calories in these blue berries, and Emma warned even overeating fruit or vegetables can lead to weight gain.

一份水果重80克，一份蓝莓的热量28卡，艾玛告诉大家，就算是蔬菜和水果，吃太多也会长肉肉的哦。

A portion of crisps is 30g, roughly equal to a normal packet of crisps, which contains 153 calories and 7.6g of fat.

一份薯片有30克，正好是一包小号包装的薯片的分量，包括153卡热量，7.6克脂肪。

The portion size for biscuits is 14g - which works out at just one biscuit if your snack of choice is a Bourbon.

一份饼干的重量是14克，如果你喜欢的是夹心饼干，一份额大概刚刚好是一块哦。