The Nottingham University study, which is funded with more than £370,000 from the Biotechnology and Biological Sciences Research Council, will focus on the chemical signals that are sent to the brain. Experts are still unsure why high-fat foods are so tasty but they do know that the taste and aroma of food, which makes up its flavour are due to special chemicals that are present in it.

These chemicals send signals through the mouth and nose to the brain and the Nottingham scientists believe that the way in which these signals affect different areas of the brain plays a large part in how much we enjoy our food.

The way in which these chemicals affect the brain may be altered by the amount of fat in food, but the pleasure we experience when eating a good meal is also affected by texture, for instance, the creaminess of an ice cream. Previous studies have shown that we prefer the texture of fatty foods.

"The taste and texture signals from the mouth and the aroma signal from the nose interact with each other in the association areas of the brain to influence our likes and dislikes for food," said professor Robin Spiller of the Universitys Wolfson Digestive Diseases Centre.

"Nottingham food scientists have shown that swallowing a food increases the delivery of the foods aroma to the nose and the thickness of food in the mouth alters taste, but we still do not know why fat has such a strong effect on increasing our preference for food."

As part of the study, the scientists want to discover how fat changes the amount of the chemicals responsible for flavour that reach the tongue and nose, and how combining these chemicals alter the flavour of food containing fat. They also want to see how this changes the brains response to food, and how the brains response to flavour is altered after a person has eaten a large, fatty meal.

To do this, they are creating some test foods, which are like milkshakes, that contain different amounts of fat. Volunteers are being asked to taste them to find out how fat alters their perception of the flavour and how much they like them.

The researchers expect that fat will alter the flavour intensity and increase the pleasantness of a food with a sweet taste and fruity aroma. Once they know how thickness, taste, aroma and fat act together to alter flavour intensity and pleasantness they will use functional magnetic resonance imaging technology to take pictures of the brain and look at which parts respond to food flavour.

Finally, they will take fMRI pictures of the brains response to a high-fat meal when taken through the mouth and then fed directly into the stomach by a tube. The researchers believe that they will see a different response in the brain when food is taken by these two methods.

The study has received industry support from food manufacturer Unilever and the research will provide vital information for the food industry to help in the development of foods that will satisfy our cravings for fat without piling on the pounds.

The study involves researchers from the Wolfson Digestive Diseases Centre, the Division of Food Sciences and the School of Physics and Astronomy.