In a new study out of the Archives of Internal Medicine investigators discovered that even people with extra copies of the “fat mass and obesity” genes called FTO did NOT get fatter if they were active throughout the day. In other words, a so-called genetic predisposition to obesity was effectively avoided when the owners of the so-called defective genes were active four to five hours a day doing low-level aerobic stuff. And it didn’t have to be much: brisk walking, housecleaning and gardening were sufficient. Just like Grok did in the original Primal Blueprint. 900 calories day of this was plenty.