I started my pre-op liquid diet yesterday. For 7 days I am allowed 3-4 protein shakes, chicken broth, and sugar free jello. Yesterday was a breeze, but today has been hell. I've had a terrible headache & the shakes all day long. My body is getting me back for the years of an unhealthy lifestyle. I am not feeling very hungry, but physically it is taking a toll on me. I am hoping that the next few days will get better.