This lesson from Yale's Low-Cost, High-Nutrition Eating for Graduate and Professional Students course, taught by Dr. Nate Wood, introduces the fundamentals of nutrition for students managing tight budgets. Wood covers the essential nutrients the body needs and explains practical ways to incorporate them into an everyday diet without overspending. The lecture sets the foundation for the rest of the course, which addresses meal planning, grocery shopping, and cooking, by first establishing the nutritional principles those later, more practical lessons will build on. It is aimed squarely at graduate and professional students balancing academic demands, limited time, and limited money.