DAILY MAIL • Fascinating images showing three portions of the same meal reveal the exact amount...

The first rules of dieting are to give up unhealthy treats and to eat less.

But a study by the British Medical Journal has revealed that most people rely on their sight to control portion sizes - which can result in them consuming an extra 300 calories a day.

Now a new series of images reveals the exact amount of food you should eat to lose, maintain or gain weight by showing three different sized portions of the same meal - and the difference in size between the smallest and largest portions is huge.

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