Research examines preferences for taste and odor in patients after Roux-en-Y gastric bypass

According to a new study from Binghamton University of Binghamton State University, after a gastric bypass type Roux-en-Y (RYGB), a type of bariatric surgery, many patients experience a decrease in taste preference for sweet and fatty foods. from New York.

Obesity is a growing epidemic around the world and one of the leading causes of death, alongside heart disease and smoking. Bariatric surgery, especially the RYGB, is the most effective treatment against obesity.

"The people who undergo this surgery are what we call morbid obesity, which means that they make at least 100 pounds of weight and that they are often diabetic," said Patricia DiLorenzo, Professor of Psychology at the University of Binghamton. "It's life or death for them."

RYGB makes the stomach much smaller in what is called a pocket. This pocket bypasses part of the small intestine, so when you eat, your food gets into a smaller stomach and empties directly into the small intestine. This means that people can no longer eat big meals, resulting in weight loss. However, taste and olfactory preferences are also known to change after surgery, and their potential involvement in the observed weight loss is a matter of study.

DiLorenzo and his research team studied changes in food and olfactory preferences after RYGB and compared them to changes in body mass index after surgery. To assess food and olfactory preferences before and after surgery, patients completed the self-assessment dummy, which assesses the reactions of pleasure and wakefulness to an object. The patients were presented with food photos representing the five taste qualities of sweet, sour, salty, bitter and umami, as well as four smells. They were then asked to evaluate their preferences. Data on BMI were collected before and after surgery.

"Most people before their surgery, their favorite foods are exactly what you expect – ice cream, fries, hamburgers, pizzas," said DiLorenzo. "But afterwards, their favorite food was salad, for example, and 20 per cent said their favorite foods were vegetables, and those who said they changed their taste preferences lost the most weight."

DiLorenzo and his team also found that people who liked more coffee after the operation were also the ones with the most weight. Coffee and vegetables have a bitter taste, indicating that the taste preferences of some patients, after foods high in fat and sweet, have evolved after RYGB, while bitter flavors were less aversive. Patients who had this effect lost the most weight and had a lower BMI in the long run after surgery.

However, these modified food preferences generally return to pre-operative preferences over time. In addition, the rate of weight loss decreases as time increases after surgery.

"Most of the weight is lost in the first year," said DiLorenzo. "After that, your weight stabilizes."

Despite the risk that some patients regain weight after the operation, the majority of patients manage to lose and maintain their weight.

"People are of the opinion that most people gain weight after RYGB surgery, and that's not true," DiLorenzo said. "Eighty percent of people keep weight.In Western medicine, it's the most effective treatment against obesity."