Why some people just can't go on diets

If you are one those you just can't control your appetite, even though you know you should diet, stop blaming yourself for a new study shows it's just how some people are wired.

According to the scientists at the Howard Hughes Medical Institute's Janelia Research Campus, the blame should be put on hunger-sensitive cells in the brain known as AGRP neurons. According to new experiments, these neurons are responsible for the unpleasant feelings of hunger that make snacking irresistible.

The negative emotions associated with hunger can make it hard to maintain a diet and lose weight, and these neurons help explain that struggle, says Scott Sternson, a group leader at Janelia. In an environment where food is readily available, their difficult-to-ignore signal may seem like an annoyance, but from an evolutionary point of view, they make sense.

AGRP neurons do not directly drive an animal to eat, but rather teach an animal to respond to sensory cues that signal the presence of food. It was suspected that these neurons were 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, said Sternson, whose team also demonstrated that a different set of neurons, known as the subfornical organ (SFO), is specialized to generate unpleasant feelings of thirst.

The study is published in the journal Nature.