Diminished taste may lead to eating more calories

31 Jul 2017 --- A potential factor in understanding obesity has been revealed with the news that people who have a dulled ability to taste food choose sweeter – and therefore likely higher-calorie – food. The results of a study by Cornell University food scientists, “Participants With Pharmacologically Impaired Taste Function Seek Out More Intense, Higher Calorie Stimuli,” could give an insight into what contributes to eventual overweight and obesity.

“We found that the more people lost sensitivity to sweetness, the more sugar they wanted in their foods,” says lead author Robin Dando, assistant professor of food science, whose research has been published online by the journal Appetite.

The findings come after nutritionists, researchers and doctors had long suspected a connection between diminished taste sensitivity and obesity, but no one had tested if losing taste altered intake. In his research, Dando temporarily dulled the taste buds of study participants and asked them to sample foods of different sugar concentrations.

For the blind tests, researchers gave participants an herbal tea with low, medium or high concentrations of a naturally occurring herb, Gymnema Sylvestre, which is known to block sweet receptors temporarily. Participants chose their own levels of sweetness to add to bland mixtures during the testing.

The participants chose 8 to 12 percent sucrose without realizing it. Soft drinks are generally around 10 percent sugar. “That’s not a coincidence,” remarks Dando. But those participants with their taste receptors blocked began to prefer higher concentrations of sugar.

“Others have suggested that the overweight may have a reduction in their perceived intensity of taste. So, if an overweight or obese person has a diminished sense of taste, our research shows that they may begin to seek out more intense stimuli to attain a satisfactory level of reward,” explains Dando. This can influence their eating habits to make up for a lower taste response, he says.

The study showed that for a regular, sugary 16-ounce (almost 500 mL) soft drink, a person with a 20 percent reduction in the ability to taste sweet would crave an extra teaspoon of sugar to reach the desired level of sweetness, as compared to someone with unaltered taste response.

“The gustatory system – that is, the taste system we have – may serve as an important nexus in understanding the development of obesity. With this in mind, taste dysfunction should be considered as a factor,” Dando says.

The sugar content of drinks has been discussed recently as it has been debated whether federal health agencies in the US should accept funding from big soda companies. Meanwhile, sugary drinks have been found to have a number of negative health effects when combined with high-protein meals, and there appears to be a trend toward soda disappearing from kids’ menus.