Research Blog
The human body is approximately 45-75% water, depending on overall health, physical activity, climate, and body size and composition. Lean tissue is 70% water, while adipose tissue only 20%.
Water is the main component of blood, tears, saliva, urine, and joint synovial fluid. Small changes in body water balance trigger a physiological response that helps retain or excrete water as needed. Failure to replace water losses results in dehydration, which can be severe and even fatal.
A water loss of 2% of body weight leads to mild dehydration and cause:
- Compromised physical performance
- Fatigue
- Headaches
- Impaired cognitive function
Although water requirements vary, according to the World Health Organization, adults require a daily total of 2.9 liters for males and 2.2 liters for non-pregnant, non-lactating females.
Water lost through urine, sweat, excess heat, diarrhea, or vomiting must be replaced to avoid dehydration and adverse consequences. Electrolytes may also need to be replaced if losses are significant.
Foods and beverages can help meet fluid requirements.
|
Food/beverage |
% Water content |
|
Tea, coffee, low-calorie soft drinks |
90–99 |
|
Beer |
90–95 |
|
Wine |
80–90 |
|
Berries, melon, citrus fruits, pears, apples, salad, vegetables, broccoli, carrots |
90–95 |
|
Milk, soft drinks, fruit juice |
85–90 |
|
Bananas, potatoes, sweet corn |
80–90 |
|
Yogurt |
75–80 |
|
Fish and seafood |
70–80 |
|
Rice and pasta |
65–80 |
|
Soup |
60–95 |
|
Stews, casseroles, etc. |
60–80 |
|
Spirits (e.g., gin, whisky) |
60–70 |
|
Pizza |
50–60 |
|
Meat |
45–65 |
|
Cheese |
40–50 |
|
Breads and biscuits |
30–45 |
|
Breakfast cereals (without milk) |
2–5 |
|
Savory snacks and confectionery |
1–10 |
While dehydration is associated with adverse consequences, including confusion, delirium, kidney failure, increased wound healing time, and increased urinary tract infection risk, overhydration has implications as well. Hyponatremia is one of the most serious consequences of overhydration and can cause headaches, fatigue, brain swelling, lung congestion, seizures, and, eventually, coma.
Optimal Takeaways
- Most adults need between two and three liters of water daily (8-12 cups)
- Water can be consumed in free water, beverages, and foods
- Water losses must be replaced to avoid dehydration and adverse consequences
Reference
Benelam, B., and L. Wyness. "Hydration and health: a review." Nutrition Bulletin 35.1 (2010): 3-25.
Additional factors
- Consume water containing adequate minerals for alkalinity and electrolyte balance.
- Drinking water should contain at least 10 mg/L of magnesium (preferably 20-30 mg/L) and at least 20 mg/L of calcium (preferably 50 mg/L).
- Be sure toxins and pharmaceuticals have been removed from drinking water, i.e., using multiple filters, carbon filtration, and reverse osmosis technology (Saini 2017).
Reference
Saini, Rummi Devi. "Health risks from long term consumption of reverse osmosis water." International Journal of Applied Chemistry 13.2 (2017): 293-301.
