No, our bodies are brilliant adapters and can run far more efficiently on fat! You do not need carbs to fuel your body and your brain - which is why a low-carb diet can be so healthy and you can feel so incredible. When your body is fuelled by a low-carb or keto diet, you achieve stable lower blood glucose levels and your body will switch from burning sugar for energy to learning how to burn fat. When you keep your carb levels low on a high-fat diet, you begin to use your glycogen stores and lower your insulin levels (the energy storage hormone). Your body starts burning fat for fuel (instead of sugar), ketones are created.  This is known as nutritional ketosis. When you are fuelled by ketones, you experience more stable energy levels, improved mood, decreased hunger, reduced inflammation, and incredible mental clarity. No more afternoon energy slumps!