WHOLE FOOD PLANT-BASED VEGAN DIET.
See Dr John McDougal, Dr Neal Barnard, T. Colin Campbell, or Dr. Caldwell Esselstyn's work for details.
Basically just what the name implies: No processed food. No animals or animal products. Fruit, vegetables, legumes, whole grains, in unlimited amounts. Small amounts of seeds and occasional small amount of nuts, raw. NO oil, no sugar, no flour (they're processed). Less than 2000mg per day of salt.