If you can't seem to stop munching on cakes, chocolates and every other kind of sweet thing, don't get angry with yourself – it's just the way you evolved.
Scientists from the Howard Hughes Medical Institute in the US have identified a bunch of cells, known as AGRP neurones, as being the cause of those nasty pangs of hunger we feel when anything delicious is presented to us, either literally or just in our minds.
When the body lacks energy, AGRP neurons become active and make us reach for the snacks. Why? Because eating reduces the activity of those brain cells and rids us of the unpleasant feeling.
The discovery, published in the journal Nature, was made by manipulating hunger signals in the brains of mice and monitoring the how they reacted in terms of searching for food.
From an evolutionary point of view, the feeling makes perfect sense – it would have caused us to put effort into searching for food at a time when it was not readily available. Not all our searches would have proved successful, so weight gain would have been unlikely. For the first time ever, we are faced with the difficult situation of having to ignore our natural inclinations if we want to stay slim.
"We suspect that these neurons are a very old motivational system to force an animal to satisfy its physiological needs. Part of the motivation for seeking food is to shut these neurons off," explained Scott Sternson, one of the lead researchers involved.