The compound works by coating fat before it is digested, stopping the enzymes that naturally break it down from working as fast as usual.

This sends a signal to the brain that a person has had enough to eat, even though their stomach may only be half full.

Experts at the Institute of Food Research in Norwich, who are yet to start tests in humans, hope to work with food manufactures in a couple of years to develop the supplement.

They are focusing on lipids found in chloroplaststhe parts of plant cells used in photosynthesis. Oats, wheat and common seeds are also a good

source of the substance. But researchers concede that manufacturers may be reluctant to add an ingredient that actually puts people off from buying more of their products.

Head of the project Dr Peter Wilde said: "Tests show that in the lab when we isolate the lipids, they can suppress appetite. In theory they could be added to any food with fat in it.

"We are still at a laboratory stage, but in two to three years we will be looking for volunteers."

There are already several food products on the market which claim to beat hunger and make you feel full. But many are based on the fibre found in whole grain.

This would be the first time that foods that do not contain fibre could be artificially engineered to induce the same feeling of being full.

Dr Wilde added: "We are not just talking about foods with oats in, this could be added to ready-meals, sauces like mayonnaise and even sugary drinks to make you eat less for the next 12 hours.'