grandriver/Getty ImagesThe keto diet is popular once again: Instagram has millions of keto-tagged posts; Pinterest is brimming with keto meal ideas; and books about ketogenic diets are among Amazon's bestselling special diet titles. Recent studies show that a ketogenic diet may also help with other neurological disorders, including ALS, Alzheimer's disease, Parkinson's and even depression. The Atkins diet is a modified version of the keto diet, and promotes a high-protein plan that phases in carbs. \"People are always looking for the next best, greatest diet, and seeing others do it led people to try the keto diet. On a keto diet, fat becomes the primary fuel source.