Question

what did the u.s. food and nutrition board recommend in 1945?
drinking eight glasses of water per day
drinking two and a half liters of fluid per day
drinking water only when thirsty
drinking water with every meal

Explanation:

In 1945, the U.S. Food and Nutrition Board recommended drinking two and a half liters of fluid per day. This recommendation included fluids from all sources, not just water.

Answer:

Drinking two and a half liters of fluid per day