After weight-loss surgery, many patients report changes in appetite, taste and smell, a new study says.
One positive aspect of these changes is that they may lead patients to lose even more weight, the researchers suggested.
The study included 103 British patients who underwent Roux-en-Y gastric bypass surgery, in which the stomach is made smaller and the small intestines is shortened. Of those, 97 percent said their appetite changed after the surgery, and 42 percent said their sense of smell changed.
Taste changes occurred in 73 percent of the patients, especially when it came to sweet and sour tastes, the researchers found. They especially noted changes in the taste of chicken, beef, pork, roast meat, lamb, sausages, fish, fast food, chocolate, greasy food, pasta and rice.
Nearly three-quarters of patients said they developed a dislike of certain foods, especially meat products. One-third avoided chicken, minced beef, beef steak, lamb, sausages, bacon or ham.
About 12 percent had an aversion to starches such as rice, pasta, bread and pastry and for dairy products such as cream, cheese, ice cream and eggs, 4 percent to vegetables, 3 percent to fruit and 1 percent to canned fish.
The researchers also found that patients with a newly developed distaste for certain foods lost an average of nearly 18 pounds more after their surgery than those whose taste wasn't affected, according to the study recently published online in the journal Obesity Surgery.
Although the study found an association between weight-loss surgery and sensory changes, it did not establish cause-and-effect.
The taste and smell changes experienced by many patients after weight-loss surgery may be due to a combination of gut hormone and central nervous system effects, according to lead author Lisa Graham, of the Leicester Royal Infirmary.
She noted that patients considering weight-loss surgery are typically told about the possible loss of taste and smell.
The U.S. National Library of Medicine has more about weight-loss surgery.