Alterations in taste and smell, including aversions to many foods, are common following gastric bypass surgery, according to a report published online in Obesity Surgery.
Most of the literature regarding gastric bypass outcomes has focused on the safety and efficacy of the procedures, while patient-reported measures such as changes in taste and smell have received comparatively little attention. The few studies that have examined this issue report high rates of alterations in taste, smell, and food preferences, affecting anywhere from 45% to 82% of patients; these changes were transient in most patients but persisted long term in approximately one-third of those affected, said Dr. Lisa Graham of the department of surgery at Leicester (England) Royal Infirmary and her associates.
They assessed such changes in a cohort study involving 103 patients who underwent Roux-en-Y gastric bypass surgery at their hospital during a 12-year period and completed a detailed questionnaire a median of 19 months afterward (range, 1-120 months). The median age of these participants was 45 years (range, 23-63 years).
A total of 75 patients (73%) reported a change in their sense of taste and 43 (42%) reported a change in their sense of smell after surgery. There was no clear pattern of change: Some patients reported that foods smelled or tasted stronger while some said they were blander, and the types of foods affected included meats, fish, starches, vegetables, fruit, dairy, and sweets, the investigators said (Obes. Surg. 2014 March 8 [doi:10.1007/s11695-014-1221-2]).
Many said that they now have strong aversions to certain foods, with 33% reporting that they could no longer tolerate the smell or taste of meats including beef, chicken, lamb, and pork. A total of 12% said that they were averse to the smell or taste of pasta, rice, and breads, and 11% said they couldn’t tolerate the smell or taste of milk, yogurt, cheese, or eggs.
The mechanism underlying these alterations is not yet known. "It is likely that a combination of gut hormone and central nervous system effects accounts for the observed changes in sensory function after weight loss surgery," Dr. Graham and her associates said.
The investigators had no relevant conflicts of interest.