These cells produce a constant stream of ghrelin whenever the stomach is empty. The ghrelin travels via the blood stream to the brain's appetite centre, an organ called the hypothalamus. As a result, the hypothalamus screams "You are hungry - find food."
But whenever the stomach wall is stretched - when the stomach is full - the cells stop producing ghrelin, and the hypothalamus responds accordingly, turning off the appetite signal. The longer the stomach remains full, the longer you feel satisfied and the less you are likely to eat.
In the battle to lose weight, hunger is the dieter's worst enemy. But research has revealed a simple aid to taming the appetite: soup
If you eat the food and drink the water, you will feel full for a couple of hours before hunger kicks in. But if you blend the food with the water - to make soup - you will stay hunger-free for much longer, and less likely to snack
When you eat the same meal as a soup, the whole mixture remains in the stomach, because the water and food are blended together. The scientists' scans confirm that the stomach stays fuller for longer,
The key to this low-tech weapon against hunger is a hormone called ghrelin