People with a reduced ability to taste food choose sweeter – and likely higher-calorie – diet, which could put them at the risk of gaining unhealthy weight, a study has found.

“We found that the more people lost sensitivity to sweetness, the more sugar they wanted in their foods,” said Robin Dando, assistant professor at Cornell University in the US.

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Nutritionists, researchers and doctors have long suspected a connection between diminished taste sensitivity and obesity, but no one had tested if losing taste altered intake.

In the study, researchers temporarily dulled the taste buds of participants and had them sample foods of varying sugar concentrations.

For the blind tests, the researchers provided participants with an herbal tea with low, medium or high concentrations of a naturally occurring herb, Gymnema Sylvestre, which is known to temporarily block sweet receptors.

During the testing, participants added their favoured levels of sweetness to bland concoctions.

Without realising it, they gravitated to 8 to 12 per cent sucrose. Soft drinks are generally around 10 per cent sugar.

“That is not a coincidence,” said Dando, lead author of the study published in the journal Appetite.

However, 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,” said Dando.

This can influence their eating habits to compensate for a lower taste response, he said.

The study showed that for a regular, sugary 470 millilitre soft drink, a person with a 20 per cent reduction in the ability to taste sweet would crave an extra teaspoon of sugar to reach an optimal 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,” said Dando.