Cancer & Ketogenic diet
In 1931 Dr. Otto Warburg won a Nobel prize for his studies on the cancer cells metabolism. Hi discovered that a difference from normal cells, cancer cells only can use glucose as a source of energy. In fact they use 200 times more glucose than a normal cell.
So a ketogenic diet (high in fat, moderate in protein, low in carbohydrates) can starve cancer cells from glucose and provide ketones that normal cells can use as an energy source.
Here, here and here are a pretty interesting talks about the subject.