Thinking yourself thinner: How remembering meals can cut appetite

British scientists have shown that actively remembering your last meal suppresses appetite and reduces the desire to snack on junk food.

They have also shown that concentrating on food while eating - rather than grabbing a meal in front of the TV - makes you less likely to get hungry later on.

The findings suggest that weight watchers can teach themselves to be less greedy - and that techniques such as hypnotism and behavioural therapy could help.

The findings come from Dr Suzanne Higgs and colleagues at the University of Birmingham who devised a series of experiments to test the impact of memory of food on snacking.

In one, 47 female students were told they were taking part in a biscuit taste test.

They were given lunch then split into two groups.

Dr Higgs told half the students to write a detailed description of their lunch, while the rest were asked to describe their journey to the campus.

After the taste test - which had been designed to disguise the true nature of the experiment - the women were invited to eat their fill of the remaining biscuits.

Women who had been asked to write a description of their lunch - making the memory of it vivid in their minds - ate far fewer biscuits than those who had been asked to describe their journey to work, New Scientist reports today.

The memory effect was small among women who took the test one hour after eating.

But it became more powerful as the day drew on. Three hours after lunch, women who had been asked to describe their meal had a "significantly reduced appetite" compared with those who did not.

In other experiments, a video was played to some of the women during the lunch to distract them.

Those who were watching the video - and not concentrating on their food - tended to snack more later in the day.

This suggests that actively concentrating on meals - rather than grabbing food in front of the television - could reduce appetite later in the day.

The part of the brain involved in remembering recent meals is the hippocampus.

The findings raise the possibility that drugs designed to boost activity in the hippocampus could suppress appetite.

Other studies have shown that those with damage to the hippocampus can lose their restraint when it comes to eating.

Dr Paul Rozin, of the University of Pennsylvania, Philadelphia, said: "Such folks will eat second and third lunches, so it makes some sense that activating the hippocampus might inhibit eating."