Keto XP Why is this good for the brain? You must have heard that ketosis is good for the brain. Why? Why does the brain benefit from something that affects the body's energy production mechanisms? This is because your brain is specific in the source from which it can derive its energy. Have you ever heard of the blood brain barrier? This is the barrier in your brain that allows many molecules and products to pass into the brain. Fat is also not easily transmitted to the brain. This is why your brain takes all its energy from glucose.