The Richard B. Russell National School Lunch Act (79 P.L. 396, 60 Stat. 230) is a United States federal law that created the National School Lunch Program (NSLP) to provide low-cost or free school lunch meals to qualified students through subsidies to schools. The program was established as a way to prop up food prices by absorbing farm surpluses, while at the same time providing food to school age children. It was named after Richard Russell, Jr., signed into law by President Harry S. Truman in 1946, and entered the federal government into schools dietary programs on June 4, 1946.
The majority of the support provided to schools participating in the program comes in the form of a cash reimbursement for each meal served. Schools are also entitled to receive commodity foods and additional commodities as they are available from surplus agricultural stocks. The National School Lunch Program serves 30.5 million children each day at a cost of $8.7 billion for fiscal year 2007. Most participants are also eligible for food during the summer through the Summer Food Service Program.
Nutrition standards for the National School Lunch Program and National School Breakfast program were updated in 2012.  This update in nutritional standards was funded through a federal statute signed into law by President Barack Obama. The bill called the Healthy, Hunger-Free Kids Act of 2010 funds free lunch programs in public schools for the next five years.  The new guidelines require students to choose either a serving of fruit or vegetables every meal. Also, the portions must now be larger. 
Along with larger portions of fruits and vegetables, the National School Lunch Program now enforces a variety of other nutritional requirements. Food products and ingredients used to prepare school meals must contain zero grams of added trans fat per serving (less than 0.5 grams per serving as defined by FDA). Furthermore, a meal can provide no more than 30 percent of calories from fat and less than 10 percent from saturated fat.
In late 2009, the Institute of Medicine of the National Academies released School Meals: Building Blocks For Healthy Children. This report reviews and provides recommendations to update the nutrition standard and the meal requirements for the National School Lunch Program and School Breakfast Program. School Meals also sets standards for menu planning that focus on food groups, calories, saturated fat, and sodium, and that incorporate Dietary Guidelines for Americans and the Dietary Reference Intakes.
Nutrition plays a critical role in cognitive development and academic performance for children; undernourished children are more likely to be less energetic and less able to concentrate. The day-to-day observation of teachers and administrators of the relationship between inadequate nutrition and behavior and ability to learn is substantiated by scientific studies. Twenty Cape Town, South Africa, children were studied for 11 years, beginning in 1955.-The study was based on the hypothesis "that the ill effects of under-nutrition are determined by (1) its occurrence during the period of maximum growth and (2) the duration of under-nutrition relative to the total period of growth. . . Evidence is cumulative and impressive that severe under-nutrition during the first 2 years of life, when brain growth is most active, results in a permanent reduction of brain size and restricted intellectual development."  Some basic micronutrients are necessary for children to maintain a good status of learning, such as iron and vitamin B-12. Iron deficiency puts a child at risk of cognitive delay and lower math scores.