Newsletter #28: GLP-1's: The Good, The Bad and The Ugly

Feb 2026

U.S. Obesity: The Big Picture

Obesity remains one of the greatest public-health challenges in the United States. For decades, obesity prevalence has hovered above 40% for adults, driven by sedentary lifestyles, highly processed foods and underlying biology. Recent surveys suggest a modest drop in national obesity rates to around 37%, coinciding with the rapid rise of GLP-1 medications for weight loss.

What Are GLP-1s? How do they work?

GLP-1 stands for Glucagon-Like Peptide-1, a naturally occurring hormone released by the gut after eating. It tells the brain you’re full, slows the emptying of the stomach, and helps regulate blood sugar. Medications in the GLP-1 class mimic this hormone by reducing appetite, slowing digestion, and improving metabolic signals. These effects help counter the biological defenses that often undermine traditional dieting.

Available GLP-1 Medications Semaglutide (Wegovy, Ozempic): Weekly injection Tirzepatide (Zepbound, Mounjaro): Weekly injection Liraglutide (Saxenda): Daily injection Oral Wegovy (oral semaglutide formulation): Daily pill

Benefits and Effectiveness- The Good Semaglutide produces approximately 11–15% body weight loss over 12 months.Tirzepatide produces approximately 16–20% body weight loss over 12 months.Additional benefits include improved blood sugar, blood pressure, and cardiovascular risk markers.

Common Side Effects- The Bad Nausea: up to 44%Diarrhea: ~23%Vomiting: ~13%Constipation: up to 29%Fatigue or headache: ~7%

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