A gram scale sat with its stainless-steel face open on Marni Rosen’s kitchen counter. Numbers flashed, calibrating the small spoonsful of high-fat cooking oil, butter and heavy whipping cream that Rosen prepared. She eyed the ticking digits to their precise tenth decimal, remembering the strict instructions from the Epilepsy Center in a local San Francisco children’s hospital. After a debilitating series of Electrical Status Epilepticus in Sleep (ESES) seizures nine years ago, Zeke, Rosen’s then 4-year-old son, began a meticulous, medically managed ketogenic diet.