This is interesting. A majority of patients who undergo gastric bypass surgery report either changes in taste and smell, or some degree of loss of these senses:

Taste, Smell and Appetite Change After Roux-en-Y Gastric Bypass Surgery, Obesity Surgery, March 2014

Of 103 patients who underwent gastric bypass surgery:

97% said they had a change in appetite
73% said their sense of taste changed
42% said their sense of smell changed

One of my graduate classes was in taste and smell. At the time, I thought it was an understudied and underappreciated field. Still do. What we call “flavor” and sometimes “taste” is actually a combination of messages sent from taste and smell receptors, as well as some other input like sight and touch (food texture).  People who lose the sense of smell from trauma experience changes in taste and flavor because these senses are interconnected.

One thing I recall about smell … it is the only sense that is picked up directly by the brain. Other senses, like touch, receive stimuli from peripheral nerves that carry the impulse to the brain, the central nervous system (CNS), to be interpreted. But smell gets picked up by CNS olfactory nerves directly, right there in a bulb at the top of the nose. Impulses from odor stimuli get sent, at least initially, to the more primitive, limbic part of the brain. The limbic system is the seat of emotions, memories, and “is highly interconnected with the brain’s pleasure center, which plays a role in sexual arousal and the “high” derived from certain recreational drugs.”  Smells can make us feel things before our consciousness kicks in.

Back to the study… Meat products topped the list of foods participants developed an aversion to, “with one in every three patients steering away from chicken, minced beef, beef steak, sausages, lamb, ham or bacon.” Other suddenly undesirable foods included fish, fast foods, chocolate, greasy foods, pasta, rice, bread, eggs, pastry, and dairy products such as cream, ice cream, and cheese. A few reported developing an aversion to vegetables and fruit.

What’s left? The pleasure in eating goes out the window.

Lead author Lisa Graham “believes the sensory changes are due to a combination of gut hormone and central nervous system effects.”

Think about that. Taste and smell will probably be altered by this surgery, perhaps permanently.  The emotions, memories, feelings, motivations, and pleasures that are impacted by smell and taste will change, may diminish, may go away completely.

Some people think a whole food plant-based diet is extreme, but they don’t think cutting out body parts is extreme.