Final answer:
Adults should consume about 3.7 liters for males and 2.7 liters for females of fluid per day according to IOM, including water from all dietary sources. The eight to ten glasses rule is a simplified guideline, and fluid needs may vary based on various factors.
Step-by-step explanation:
The recommended daily fluid intake for adults, according to the Food and Nutrition Board of the Institute of Medicine (IOM), is roughly 3.7 liters (15.6 cups) for adult males and about 2.7 liters (11 cups) for adult females. This total includes water from all dietary sources, meaning both fluids consumed as beverages and water content found in food. It's therefore more than the commonly cited eight to ten 8-ounce glasses per day, which is a simple rule of thumb rather than a specific guideline from health authorities.
These recommendations take into account not only drinking water but also the water gained from solid foods and other beverages. Moreover, individuals should adjust their intake depending on the climate, their activity level, and their health. While excessive water intake is rare, it can lead to water intoxication. Conversely, dehydration is much more common and can have significant health consequences.