Obesity can weaken response to taste

Washington: Obesity is linked to a reduced response to taste, reveals a recent study.

According to the study published in the journal 'Frontiers in Integrative Neuroscience,' taste perception is known to change with obesity, but the underlying neural changes remain poorly understood.

"It is surprising that we know so little about how taste is affected by obesity, given that the taste of food is a big factor in determining what we choose to eat," said Patricia Di Lorenzo, professor of psychology, Binghamton University.

To address this issue, a team of researchers including Di Lorenzo and former graduate student Michael Weiss aimed to detail the effects of obesity on responses to taste stimuli in the nucleus tractus solitarius, a part of the brain involved with taste processing.

The researchers recorded the responses to taste stimuli from single cells in the brainstem of rats that were made obese by feeding a high-fat diet.

They found that taste responses in these obese rats were smaller in magnitude, shorter in duration and took longer to develop, compared with those in lean rats.

The results suggested that a high-fat diet produces blunted, but more prevalent, responses to taste in the brain and a weakened association of taste responses with ingestive behaviour.

While Di Lorenzo stressed that these findings currently only apply to rats, she said that this same process could possibly translate to humans.

"Others have found that the number of taste buds on the tongue is diminished in obese mice and humans, so the likelihood that taste response in the human brain is also blunted is good," said Di Lorenzo.