Metabolic HealthTirzepatide Cuts Meal Calories by 59% in Just 3 Weeks, Brain Scans Reveal Why
A 6-week randomized trial in 114 adults with overweight or obesity found that tirzepatide (the GIP/GLP-1 dual agonist in Mounjaro/Zepbound) reduced calorie consumption at a test meal by roughly 532 kcal — a 59% drop — after just 3 weeks, compared to near-zero change with placebo. By week 6, the reduction deepened to 658 kcal (72%). The drug also curbed appetite, food cravings, hunger, and susceptibility to food cues in the environment. Brain imaging revealed reduced activation in the orbitofrontal cortex, medial frontal gyrus, cingulate gyrus, and hippocampus in response to high-fat, high-sugar food photos — regions tied to food reward and memory. Liraglutide also reduced intake but significantly less than tirzepatide.
