Smell loss is more common in obesity and type 2 diabetes than most people realize, affecting up to half of patients. Research suggests the link runs deep — olfactory dysfunction may actually reinforce unhealthy eating patterns. The good news? Bariatric surgery can rapidly restore smell, even before significant weight loss occurs.
Most people know that obesity and type 2 diabetes can damage eyesight, hearing, and nerve sensation. But a growing body of research points to another underappreciated casualty: the sense of smell. In a Q&A with Medscape, neuroscientist M. Hirac Gurden, PhD, explains how olfactory dysfunction is both a consequence of metabolic disease and a potential contributor to it — creating a feedback loop that makes healthy eating even harder.
Gurden's research highlights that GLP-1 signaling in the olfactory bulb plays a role in regulating pancreatic insulin secretion in mice, suggesting the brain's smell center is more metabolically active than previously thought. He also notes that olfactory loss may bias patients toward highly palatable, processed foods — reinforcing automatic eating patterns and worsening nutritional outcomes.
By the Numbers
Why it matters: Olfactory screening in obesity clinics could become a meaningful clinical tool. Simple interventions — like encouraging patients to smell food before eating and diversify their diets — may help restore sensory engagement with food and support healthier eating behaviors.
