Common nutritional mistakes made by fitness enthusiasts include excessive reliance on sugary energy drinks or bars instead of whole foods, leading to spikes in energy followed by crashes. Another mistake is neglecting hydration, which is crucial for optimal performance and recovery. Many also overlook the importance of post-workout nutrition, leading to inadequate muscle repair. Additionally, some individuals might focus excessively on macronutrient counts, such as protein, at the expense of essential vitamins and minerals. A balanced, varied diet that meets energy demands is crucial for sustaining fitness goals.