Delboeuf Illusion

How do you know that you have eaten enough? One way is to know the ingredients, weigh everything and measure the calorific value and nutrients of what you have just eaten. Imagine doing that for President Obama’s farewell dinner. I doubt you would be invited back for the next President’s inaugural ball. In reality it is nigh impossible to calibrate what you eat and your body takes up to 20 minutes to signal to your brain that you are satiated. It does this by regulating the release of a hormone called  cholecystokinin or CCK. Interestingly, if you are dieting, it will release less CCK to encourage you to eat more.

As all of this takes place within, your body has to rely on everyday tools to determine how much to eat. We therefore use our eyes to understand the quantum of food consumed and decide when is enough. This is tricky as your eyes are really not the best judge and also easily fooled. I know in my own case, I was eating 200 gms of cottage cheese imagining it to be 50 gms. It was only when I weighed it did I realise that I was over eating by four times.

If this was not hard enough, it now turns out that the size of the serving plate can significantly alter your perception of the amount of food you are eating. In 1865 Delboeuf documented the puzzling perception of two identical sized circles appearing to be of different sizes when surrounded by two circles one of which was smaller than the other. This became known as the Delboeuf principle. Applied to food, if you use bigger plates, chances are you might end up serving yourself more food. Your eyes get fooled into thinking that you have not eaten enough and your body takes way to long to signal – enough! I always told everyone who would care to listen that it was not my fault I was eating so much,  but no one listened. Now I can say “the fault does not lie in our stars but in our plates that we are so over-weight


Ritesh is a born again health enthusiast and holds a Certificate in Physiology from Harvard Medical School and a Certificate in Nutrition from Tufts University.