Scientists have discovered the secret to weight loss and regulating diet.

Experts from the University of Sussex have found the presence of umami – which is known as the fifth taste sense – helps reduce appetite whilst also making food tasty.

Umami, which means delicious in Japanese, is a protein found in meat and other savoury foods such as Marmite, parmesan and shiitake mushrooms, which gives food its tastiness.

It is the fifth taste sense along after sweet, salty, sour and bitter.

Professor Martin Yeomans was involved in the University of Sussex study based on the psychology research of Dr Una Masic.

He said: “We know from past research, including previous work at Sussex , that foods with a high protein content tend to satisfy your appetite better than carbohydrate and fat-rich foods.

“So if protein is satisfying, and umami signals the presence of protein; in this study we asked whether the presence of the umami taste itself reduced subsequent appetite.”

The research, published in the American Journal of Clinical Nutrition, looked at the effects of two common food additives on levels of hunger: monosodium glutamate (MSG) and inosine monophosphate (IMP), which are known to produce the flavour of umami.

They were added to both a low-energy version of a spiced carrot soup and the same soup with energy added covertly as a mixture of protein and carbohydrate.

Dr Masic then tested how hungry 26 healthy volunteers felt and how much they consumed at a later meal.

The soups enhanced with the umami-taste were found to reduce the amount subsequently eaten by participants when compared to the same soup without added umami, tests suggested.

Those who ate the umami soup also did not feel hungrier as a consequence of eating less, the university spokeswoman said.

The effects of umami proved stronger when consumed in the higher-energy soup which suggested that umami-enriched foods may help people with weight concerns to regulate their appetite.