By the time she had reached her mid-30s, Tana Amen had nearly given up on good health. Through a lifetime of chronic medical ailments, including severe digestive issues, recurrent infections and, most devastatingly, a battle with thyroid cancer, there was never a point when Tana felt consistently healthy. Doctors ascribed her poor health to genetics, bad luck, and a family history of obesity and heart disease. But even when Tana committed to a standard fitness and eating regimen, her health fail