By Esther Kerina, Consultant Dietician at Aga Khan University Hospital Nairobi
Portable plastic water bottles have become very common these days especially among women, and a small number of men as more and more people are becoming aware of the importance of staying hydrated. Changing climatic condition with high temperatures either at night or during the day have also contributed to the trends.
Your body needs an adequate amount of water to function properly as your brain, blood and bones are composed of high water content. When you’re low on fluids, the brain triggers the body’s thirst mechanism that prompts you to drink water.
So, how much water should you drink each day? It’s a simple question with no easy answer.
Studies have produced varying recommendations over the years. But your individual water needs depend on many factors, including your age, overall health, how active you are and environmental factors.
No single formula fits everyone. But knowing more about your body’s need for fluids will help you estimate how much water to drink each day.
Health benefits of water
Water is your body’s principal chemical component and makes up about 60 percent of your body weight on average.
Every cell, tissue and organ in your body needs water to work properly. For example, water helps maintain electrolyte (sodium) levels. These electrolytes help balance body organ activity and functions, water also aids in digestion of food, gets rid of wastes through urination and bowel movements. Adequate hydration keeps things flowing along your gastrointestinal tract and prevents constipation. Water keeps your temperature normal, lubricates the skin and cushions joints. Our skin contains plenty of water, and functions as a protective barrier to prevent excess fluid loss as well as protecting sensitive tissues.
Lack of water can lead to dehydration which occurs when you don’t have enough water in your body to carry out normal functions. Even mild dehydration can drain your energy and make you tired and get headaches.
Always evaluate your water intake when you get headaches before you rush to get pain killers. Some headaches are triggered by dehydration.
Signs that can tell you are dehydrated wil include feeling tired, headaches, dark urine, low blood pressure and dizziness and confusion.
How much water do you need?
Every day you lose water through your breath, perspiration, urine and bowel movements. For your body to function properly, you must replenish its water supply by consuming beverages and foods that contain water.
An average adult weighing about 70kgs requires about 6 – 8 glasses of water for women and 8 – 10 glasses for men in a day.
These recommendations cover fluids from water, other beverages and food. About 20 percent of daily fluid intake usually comes from food and the rest from drinks.
Factors that influence your water needs
Age. Infants and growing children have much greater fluid turnover than adults because their higher metabolic rate increases fluid loss. Infants lose more fluid through the kidneys because immature kidneys are less able to conserve water than adult kidneys.
Overall health. Your body loses fluids when you have a fever, vomiting or diarrhea. Drink more water or follow a doctor’s recommendation to drink oral rehydration solutions. Other conditions that might require increased fluid intake include bladder infections and urinary tract stones.
Exercise. If you do any activity that makes you sweat, you need to drink extra water to cover the fluid loss. It’s important to drink water before, during and after a workout. If exercise is intense and lasts more than an hour, a sports drink can replace minerals in your blood (electrolytes) lost through sweat.
Pregnancy or breast-feeding. Women who are pregnant or breast-feeding need additional fluids to stay hydrated. A doctor or registered dietitian can help you determine the amount of water that’s right for you every day.
Environment. Hot or humid weather can make you sweat and requires additional fluid intake. Dehydration also can occur at high altitudes.
Other sources of water
You don’t need to rely only on what you drink to meet your fluid needs. What you eat also provides a significant amount of water. For instance, many fruits and vegetables, such as watermelon and spinach, are almost 100 percent water by weight. But water is your best bet because it’s calorie-free, inexpensive and readily available.
How safely hydrated are you?
Your fluid intake is probably adequate if you rarely feel thirsty and when your urine is colorless or light yellow.
To prevent dehydration and make sure your body has the fluids it needs, make water your beverage of choice. It’s also a good idea to drink a glass of water or other calorie-free or low-calorie beverage with each meal and between each meal, drink water before, during and after exercise and drink water if you’re feeling hungry. Thirst is often confused with hunger.