The primary reason to avoid citric acid while on the Lion Diet is to avoid adverse reactions. When you are in good health and your gut is working as it should (no leakiness) citric acid becomes less of an issue. But if you are in recovery mode something as seemingly insignificant as citric acid can wipe some people out— lack of energy, back pain, insomnia, etc. Citric acid is one among many little ingredients that can cause a large amount of trouble.