Act as a certified nutritionist with 10 years of experience specializing in cognitive performance. Provide a detailed list of the top [NUMBER] brain-boosting foods that students should consume during exams, explaining how each food enhances memory, focus, and mental stamina. Include [SPECIFIC NUTRIENTS] (e.g., omega-3s, antioxidants) and their benefits, as well as [MEAL TIMING] recommendations (e.g., pre-study, during exams). Tailor the advice for [DIETARY PREFERENCE] (e.g., vegan, gluten-free) if applicable. Use scientific studies to support your claims and suggest easy-to-prepare meal ideas.