Incretins Boost Taste, Cut Appetite

About one in five of those participating in the real-word study, published in the journal Diabetes, Obesity and Metabolism, perceived sweetness more intensely and a similar number were more sensitive to salt - and these changes were linked to a reduction in appetite.

"Incretin-based therapies such as Ozempic, Wegovy and Mounjaro are widely used for weight management but their effect on taste perception has been unclear," says Othmar Moser, of University of Bayreuth, Bayreuth, Germany, who led the research.

"If changes in taste are linked to greater appetite control and weight loss, this could help clinicians better select therapies, provide more tailored dietary advice and improve long-term treatment outcomes for patients."

To find out more, Professor Moser and colleagues from the Medical University of Vienna surveyed hundreds of individuals with overweight and obesity who were taking Ozempic, Wegovy or Mounjaro for weight loss about their sense of taste and appetite.

Of the 411 participants (69.6% female), 148 were on Ozempic, 217 were on Wegovy and 46 were taking Mounjaro.

Median duration of treatment was similar for the three groups (Ozempic: 43 weeks; Wegovy: 40 weeks; and Mounjaro: 47 weeks), with all of the participants receiving treatment for at least three consecutive months. The average BMI before starting treatment was 34.7 kg/m2 (Ozempic), 35.6 kg/m2 (Wegovy) and 36.2 kg/m2 (Mounjaro).

The participants, who were recruited online, were asked if their sense of taste (perception of sweetness, saltiness, sourness and bitterness) had changed since starting treatment.

They were also asked about changes to appetite, satiety and food cravings, as well changes to lifestyle factors, such as smoking, and for self-reported data on height and weight before and during treatment.

Reductions in BMI, adjusted for duration of treatment, dose, baseline BMI, age and sex, were 17.4% with Ozempic, 17.6% with Wegovy and 15.5% with Mounjaro.

Around a fifth of the participants said that food tasted sweeter (21.3%) or saltier (22.6%) than before. Their perception of bitterness and sourness did not change.

Some 26.7% of participants in the Wegovy group reported that food tasted saltier than before, compared with 16.2% in the Ozempic group and 15.2% in the Mounjaro group. Increases in sweetness were reported at similar frequencies in all groups (Wegovy 19.4%, Ozempic 21.6%, Mounjaro 21.7%).

More than half of the participants (58.4%) reported they were less hungry in general, i.e. their appetite had decreased (Ozempic: 62.1%, Wegovy: 54.4%, Mounjaro: 56.5%).

Almost two-thirds of the participants (63.5%) reported increased satiety i.e. they felt full sooner Ozempic: 58.8%, Wegovy: 66.8%, Mounjaro: 63.1%). Food cravings were also reduced, with 41.3% of Mounjaro users reporting a strong reduction in cravings, i.e. their cravings were much less intense that before, compared with 34.1% of those taking Wegovy and 29.7% of those taking Ozempic.

Further analysis revealed links between changes to sense of taste and appetite and satiety.

Participants who reported that food tasted sweeter since starting incretin-based therapy were twice as likely to report increased satiety, compared with participants who said their perception of sweetness had not changed.

Those with an increase in the perception of sweetness were also 67% more likely to report a reduction in appetite and 85% more likely to report a reduction in cravings, compared with those whose perception of sweetness was unchanged.

Similarly, participants who said food tasted saltier than before were about twice as likely (2.17 times) to also reported increased satiety, compared with those whose perception of saltiness was unchanged.

Professor Moser says: "These drugs act not only in the gut and brain areas that control hunger but also on taste bud cells and brain regions that process taste and reward. This means they can subtly change how strong flavours, like sweetness or saltiness, are perceived. This, in turn, may affect appetite."

However, there was no link between changes in taste perception and reduction in BMI. The researchers speculate this is because sense of taste is just one of many factors involved in weight loss.

Professor Moser explains: "Shifts in taste may affect how satisfying or appealing food feels in the moment, which influences appetite control. However, weight loss depends on many other factors - like metabolism, long-term eating patterns, and activity - so changes to taste alone may not be enough to directly drive body weight reduction."