Gene mutation linked with preference for high fat, less sugar in adults

The melanocortin-4-receptor protein is key to modulating food preference in humans and can have a unique influence on adults with obesity,” researchers found. The study revealed that “in adults with and without obesity with a melanocortin-4-receptor (MC4R) mutation,” there appears to be “an increased craving for high-fat foods, but a decreased craving for high-sucrose food.” The findings were presented at Obesity Week 2016. The MC4R mutation also has another surprising benefit. Despite having even severe obesity, many adults with the mutation are protected from hypertension, Farooqi said. In studies with diet-induced obese mice, the obese mice would develop hypertension, whereas the obese mice lacking leptin or a leptin receptor would not develop hypertension, despite a high-fat diet, Farooqi said. “What this means is leptin is a key signal linking weight and blood pressure,” Farooqi said. “The pathway looks something like this: If you have more fat, you make more leptin. Leptin goes to the brain, acts in the hypothalamus on this melanocortin circuit, and if you have increased leptin with obesity, you get increased tone through this circuit.” That increased tone, Farooqi said, ultimately increases sympathetic tone, driving up heart rate, blood pressure and the blood pressure response to stress. “This pathway is a key reason why as people gain weight, their blood pressure goes up, and as they lose weight their blood pressure goes down,” Farooqi said. “That is a physiological response mediated by leptin and these circuits.” – by Regina Schaffer http://www.healio.com/endocrinology/obesity/news/online/%7Bd8eb4e0c-d9fe-433f-a262-51823650bbb8%7D/gene-mutation-linked-with-preference-for-high-fat-less-sugar-in-adults