The impact of chemosensory dysfunctions on weight loss

Background: The role of chemosensory senses (olfaction, taste, and trigeminal) is crucial, and their dysfunctions profoundly affect the quality of life, potentially impacting eating behaviors. However, it is unclear which chemosensory symptoms could lead to undernutrition. This study aims to investigate which findings in patients9 smell and taste workup are predictors of weight loss. Methods: This is a retrospective study based on a validated questionnaire consecutively given to adult patients presented in smell and taste consultations during a 10-year period. Psychophysical tests were used to measure chemosensory function (Sniffin9 Sticks, taste powder, and Taste Strips tests). Results: We included 555 patients (307 females) with a median age of 51 years (IQR 23). Among them, 76 (13.7%) reported involuntary weight loss due to chemosensory disorders occurred over periods ranging from 3 to 36 months. We found that the odds of losing weight were 2.1 times higher when patients reported changes in aroma perception (p-value=0.012; 95% CI 1.15 - 3.83). Parosmia, but not phantosmia nor smell loss, was a significant predictor of weight loss (OR 2.22; p-value=0.015; 95% CI 1.17 - 4.2). Furthermore, the duration of symptoms for more than two years was protective for weight loss (OR 0.44; p-value=0.014; 95% CI 0.23 - 0.85). Regarding putative etiologies, post-traumatic chemosensory dysfunction was also a significant predictor (OR 2.08; p-value=0.039; 95% CI 1.04 - 4.16). Concerning psychophysical tests, we found that the probability of a patient to present weight loss increased by 8% for every 1-unit reduction in Taste Strips score (p-value=0.006; 95% CI 0.87 - 0.98). Conclusion: We recommend investigating weight loss in smell and taste consultations, especially when patients report changes in aroma perception, parosmia, duration of symptoms for less than two years, head injury, and when low Taste Strips score is measured.