A newly discovered ability for people to taste fat could hold the key to reducing obesity, Deakin University health researchers believe.

Deakin researchers Dr Russell Keast and PhD student Jessica Stewart, working with colleagues at the University of Adelaide, CSIRO, and Massey University (New Zealand), have found that humans can detect a sixth taste -- fat. They also found that people with a high sensitivity to the taste of fat tended to eat less fatty foods and were less likely to be overweight. The results of their research are published in the latest issue of the British Journal of Nutrition.

"Our findings build on previous research in the United States that used animal models to discover fat taste," Dr Keast said.

"We know that the human tongue can detect five tastes -- sweet, salt, sour, bitter and umami (a taste for identifying protein rich foods). Through our study we can conclude that humans have a sixth taste -- fat."

The research team developed a screening procedure to test the ability of people to taste a range of fatty acids commonly found in foods.

They found that people have a taste threshold for fat and that these thresholds vary from person to person; some people have a high sensitivity to the taste while others do not.

"Interestingly, we also found that those with a high sensitivity to the taste of fat consumed less fatty foods and had lower BMIs than those with lower sensitivity," Dr Keast said.

"With fats being easily accessible and commonly consumed in diets today, this suggests that our taste system may become desensitised to the taste of fat over time, leaving some people more susceptible to overeating fatty foods.

"We are now interested in understanding why some people are sensitive and others are not, which we believe will lead to ways of helping people lower their fat intakes and aide development of new low fat foods and diets."