Here are some great articles on how to study better, while taking care of yourself:

• Tumblr user explains how to study like a Harvard student and every student should read it: https://www.google.com/amp/s/www.rearfront.com/study-like-harvard-student/amp/  
• Nutritious meals make better grades:  http://www.chicagotribune.com/business/sns-health-nutrition-better-grades-story.html#
•  Diet quality and academic performance: https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1746-1561.2008.00288.x