Coming to Terms with the Biology of Desire

Prudence and DesireO‌‌ne of the neat tricks of semaglutide and tirzepatide is their unexpected ability to shift the frames of bias through which we look at obesity and human behavior. Neuroscience and behavioral psychology have long told us the human desire for food is not purely a matter of choice. Yet in addressing obesity, weight bias and misconceptions have kept the public and many health professionals from facing this truth. Now, with drugs that effectively quiet abnormal preoccupation with food, many more people are coming to terms with the biology of desire.

Writing in the New York Times, Maia Szalavitz welcomes this:

“It is long past time to stop shaming people with disorders of appetite in a futile attempt to tame our own fears of loss of control. Whatever condition is being treated, we all deserve the easiest possible path to recovery. Understanding how wanting, liking and attention are regulated by the brain could lead to better self-control for many, across diagnoses‌.”

Quieting the “Food Noise”

Food noise” is getting a lot of attention in popular media reports about incretins like semaglutide or tirzepatide. People say that noise recedes when they take these drugs for obesity. Perhaps with good reason. Clinical trials show that even liraglutide – a GLP-1 agonist and the first incretin approved for obesity treatment – a can help reduce a person’s preoccupation with food.

We live in a world filled with food cues that prompt intrusive thoughts about food. This is one way our environment promotes obesity in susceptible individuals. So the activity of incretins in the central nervous system to reduce the neural effects of those prompts is quite important.

Dysregulated Appetites

Szalavitz sees obesity as just one of many problems that people face with dysregulated appetites. She sees parallels with drug addiction, sexual desire, and other compulsive behaviors. Neuroscience is helpful for understanding how our brains regulate those desires. It is not a simple matter of self-control and behavioral choice. Research on the incretins for alcohol use disorder and other problems related to reward pathways in the brain is certainly intriguing.

Some people, such as neuroscientist Marc Lewis, see problems with medicalizing behavioral problems such as addiction. To be sure, we should be careful about setting up a false dichotomy between behavior and biology – whether the subject is obesity, alcohol, or drug use.

But we fully agree with Szalavitz. Blame and stigma for disorders of appetite take us to a dead end. Understanding the biology of desire can help us avoid that mistake.

Click here for Szalavitz’s commentary. For more on research aimed at understanding the activity of newer incretins in the brain, click here.

Prudence and Desire, pencil and watercolor by Frances Macdonald MacNair / WikiArt

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June 5, 2023