The most common allergies that can impact nutrition include reactions to foods like peanuts, tree nuts, dairy, eggs, wheat, soy, fish, and shellfish. These allergies can lead to a range of symptoms, from mild discomfort to severe, life-threatening reactions. Individuals with food allergies must carefully manage their diets to avoid allergens, often resulting in nutrient deficiencies if replacement foods are not adequately chosen. Education on reading labels and recognizing hidden allergens is crucial for safe and balanced nutrition for those affected.