Deakin University researchers have found a reason as to why people overeat.

Researchers said that the answer lies in the taste of the food. People, who do not taste fat in food, are more likely to overeat and face a heightened risk of becoming obese. They tend to eat more food at lunch even after having a fat-rich breakfast.

The findings support previous claims that linked taste of fat with obesity. Obesity results in several health complications including heart disease and diabetes.

"These results suggest that the ability to taste fat is linked with the fullness experienced from fat," said Professor Russell Keast, a researcher in sensory science, in a statement. "If you do not taste fat or experience the fullness associated with eating fatty food, you are more likely to be hungry and consume more energy after an earlier fatty meal."

"And as we know, over-consumption of foods - particularly fatty foods - is associated with people being overweight or obese."

For the study, researchers tested participants' sensitivity to fat taste while they consumed a high-fat, high-carbohydrate and high-protein breakfast over four separate days. Then they had a buffet-style lunch with a variety of foods until they felt full. The participants' hunger and fullness and their calorie consumption were recorded.

Keast said that inability to taste fat is one of the factors that cause the development of obesity. People who have highly sensitive taste buds are more likely to eat fatty foods in lesser quantities. While those with lower sensitivity - who cannot taste fat - are more likely to eat fatty foods.

The researcher said that a lack of sensitivity to fat-taste impairs the body's ability to receive fullness signals. Keast suggests increasing fat-taste sensitivity in people who cannot taste it in order to solve the growing obesity problem.

The finding adds to Keast's previous work that found fat is part of the tongue's taste range along with sweet, salt, sour, bitter and umami.

Previous studies showed that a diet rich in fat content makes people addicted to fatty foods resulting. The addiction further causes depression and changes the brain's circuitry.

"In addition to causing obesity, rich foods can actually cause chemical reactions in the brain in a similar way to illicit drugs, ultimately leading to depression as the 'come-downs' take their toll. We are demonstrating for the first time that the chronic consumption of palatable, high-fat diets has pro-depressive effects," said Researcher Stephanie Fulton from the University of Montreal Hospital, in a press release.

The findings are published in the journal Appetite.