How do you know when you are full?

The definition of satiety as taken from the Encyclopedia Britannica goes as follows

“desire to limit further food intake, as after completing a satisfying meal. The hypothalamus, part of the central nervous system, regulates the amount of food desired. Eating is thought to increase the body temperature, and as the temperature in the hypothalamus rises, the process of feeding decreases. Satiety is reached long before the food is digested or absorbed. In humans a number of factors may be involved in limiting food consumption. The feeling of fullness caused by distention of the stomach can stop further eating. A large quantity of sugar in the bloodstream or a large amount of stored fat tissue may inhibit ingestion…….”

Traditionally researchers have said that it usually takes up to 20 minutes before our brain picks up the signals that the stomach is full. The stomach’s stretch receptors take about 20 minutes to tell the brain how full the stomach really is.

These days food is extremely calorie dense and meals are eaten in a hurry. As a result, one can eat a lot of calories in less then 20 minutes before the brain picks up the “full” signals.

Another major problem is that we have been programmed from young to “finish the food on our plates because there are many starving people in Africa”. I definitely empathize with the poor people who do not get sufficient food but can somebody explain to me how me finishing my food is going to fill the belly of someone in Africa.

By us finishing the food on our plates just for the sake of finishing it is only going to load us up with calories. I don’t see any of it going to our African brothers! We get fatter while our African brothers continue to be deprived.

Here is a revelation for everyone. It is OK to leave unfinished food on your plate. It won’t make starvation in Africa worst and it also won’t make you fatter!

The inhabitants of Okinawa, which is a collection of over a hundred islands off the coast of Japan,  have some of the world’s longest life spans and best health. You also hardly find an overweight Okinawan.

Okinawans live by the Confucian-inspired adage “hara hachi bu–Eat until your stomach is 80 percent full.”

Stopping at 80% capacity is actually a very good strategy to avoid obesity without going hungry as it can take up to 20 minutes for the brain to register that one is full.

While this may still be true, visual cues play a much more significant role in determining when we really stop eating.   We roughly estimate how much we want to eat, dish it out and continue to put food into our mouths until our plates are wiped clean.

Let us go back to the Cornell University Food and Brand Lab where Dr Brian Wansink conducts some of the most intriguing experiments to find out why we eat mindlessly?

In an earlier experiment of Dr Wansink, he asked 150 people from Chicago and 150 people from Paris how they knew that their dinner was over.

The 150 people from Paris knew their dinner was over when they felt full. The 150 people from Chicago on the other hand knew their dinner was over when;

• The food on their plates was finished
• Other people had finished their food
• The TV program was finished

The “Bottomless Soup Bowl Experiment” was one of Dr Wansink’s most ingenious experiments. This was an experiment to find out what happens when the plate never empties.

People just continued eating as long as the soup was in the soup bowl, seeming to also bypass the inbuilt “satiety” signals being sent to the brain. When asked, people answered, “How can I be full. I still have not finished the soup in the bowl!”.

Dr Brian Wansink’s experiments tell us that while there is an inbuilt mechanism that takes 20 minutes to sense satiety, we can overrule it if we still see unfinished food on our plates! We can overrule it if we eat mindlessly!