Building a strong immune system through diet involves consuming a variety of nutrient-dense foods. Key nutrients include vitamin C from fruits and vegetables, zinc from legumes and seeds, and probiotics from fermented foods. These nutrients help support the production of white blood cells, which are essential for fighting infections. Additionally, a diet rich in antioxidants helps combat oxidative stress. Staying hydrated and limiting processed foods also plays a role in maintaining optimal immune function, making a balanced diet crucial for overall health.