A balanced diet containing protein, fat, carbohydrates, fiber, vitamins and minerals is needed to sustain a healthy body. Rather than eliminating food groups, one should select the healthiest options within each category. Protein provides energy and supports mood and cognition, though too much can harm those with kidney disease; many may benefit from more high-quality protein as they age. Carbohydrates are the main energy source and should come from complex, unrefined sources rather than sugars and refined carbs. While bad fats can be harmful, good fats like omega-3s protect the brain and heart and are vital to overall health.