The objective of a ketogenic diet is to help the body use fuel more efficiently. Think about it this way: When your car gets better gas mileage, it winds up using less gas. The same can be true for us: On the keto diet, we get more mileage out of the food we consume, and therefore we end up eating less. One 2015 meta-analysis found that the keto diet suppresses appetite2, causing us to consume fewer unnecessary calories. Moral of the story: No matter what kind of diet you choose, there will always be a way to minimize its impact on the environment.