Hydration Guidelines

The Institute of Medicine of the National Academy of Sciences conducted an extensive analysis on the research concerning hydration and released fluid intake recommendations in their 2004 report.

Highlights from the IOM report:

  • About 80 percent of people’s total water comes from drinking water and beverages — including caffeinated beverages – and the other 20 percent is derived from food.
  • The scientific panel did not offer any rule of thumb based on how much plain water people should drink each day because hydration needs can be met through a variety of sources in addition to drinking water. Keep in mind though that the report refers to total fluid, which includes the water contained in beverages and the moisture in foods, to avoid confusion with drinking water only.
  • Most people can meet their daily hydration needs with their normal drinking behavior. While drinking water is a frequent choice for hydration, people also get water from juice, milk, coffee, tea, soft drinks, fruits, vegetables, and other foods and beverages as well. On a daily basis, most people get adequate amounts of water from normal drinking behavior — consumption of beverages at meals, snacks and in other social situations — and by letting their thirst guide them.
  • When it comes to meeting daily water and hydration needs, not only non-caffeinated beverages, but also caffeinated beverages can contribute. Thus, all beverages, including caffeinated beverages, are hydrating – juice, soft drinks, tea, milk, water and coffee. While concerns have been raised that caffeine has a diuretic effect, available evidence indicates that this effect is transient, and there is no convincing evidence that caffeine leads to dehydration.

Institute of Medicine of the National Academy of Sciences Hydration Guidelines

Age Range Daily Water Adequate Intake
Infants
0-6 months 3 cups* (0.7 L), assumed to be from human milk.
7-12 months 3.5 cups (0.8 L), assumed to be from human milk and complementary foods and beverages.

This includes ~3 cups (0.6 L) as total fluid, including formula, juices and drinking water.

Children
1-3 years 5.5 cups (1.3 L) total water,** including ~4 cups (0.9 L) as total beverages, including drinking water.
4-8 years 7.5 cups (1.7 L) total water, including ~5 cups (1.2 L) as total beverages, including drinking water.
Adolescents Males Females
9-13 years 10.5 cups (2.4 L) total water, including ~8 cups (1.8 L) as total beverages, including drinking water. 10 cups (2.3 L) total water, including ~8 cups (1.8 L) as total beverages, including drinking water.
14-18 years 14 cups (3.3 L) total water, including ~11 cups (2.6 L ) as total beverages, including drinking water. 9 cups (2.1L) total water, including ~7 cups (1.6 L) as total beverages, including drinking water.
Adults Males Females
19-70+ years 16 cups (3.7 L) total water, including ~13 cups (3 L) as total beverages, including drinking water. 11.5 cups (2.7 L) total water, including ~9 cups (2.2 L) as total beverages, including drinking water.
* 1 cup equals 8 fluid ounces (~240 ml). Figures rounded up to the nearest 10 ml.

** “Total water ” includes fluids from all foods and beverages consumed.