Your liver gets the blame for your cholesterol. But part of the instructions come from your brain. MC4R is a receptor in the brain that regulates appetite. About three in a thousand people carry a broken MC4R gene copy, and they gain weight early and heavily. Researchers at @Cambridge_Uni and @unige_en compared these carriers with 336,728 people in the @uk_biobank. Correcting for the weight itself, the carriers had lower cholesterol and triglycerides. A meal test caught the same effect in real life. 11 carriers, 15 controls matched for weight, a 674 calorie meal at 60 percent fat. The triglyceride spike was about half as big in the carriers. In the same biobank, common obesity built from many small variants carried clear extra heart risk. Obesity from this one broken receptor showed no detectable increase in that risk. Same weight on the scale. Different consequence, depending on the route that produced it. Zorn et al., @NatureMedicine 2025. This paper went through Claims this week: 8 claims, each tied to the evidence behind it. @Farooqi_Lab