It may only be four letters, but it is one trending diet program: keto.

Jacqueline Hollywood, M.D., a board certified in cardiologist and nuclear cardiologist at Hackensack Meridian Health Medical Group, helps to digest this fat-packed diet. As someone who has tried the diet in the past and noticed temporary weight loss, Dr. Hollywood distinguishes a ‘dirty’ keto plan from a healthy, ‘clean’ keto.