In the ketogenic diet, macros refer to the three main nutrients your body needs: fats, proteins, and carbohydrates. On this diet, you eat mostly fats, a moderate amount of protein, and very few carbs. This helps your body switch from using sugar (from carbs) for energy to burning fat instead.

For people dealing with cancer, this switch can be helpful because some research suggests that cancer cells feed on sugar, so reducing carbs might slow their growth. Fats give you energy, protein helps you heal and stay strong, and cutting carbs can help your body focus on fighting the disease.