FLUID CONUNDRUM: HOW MUCH WATER DO I NEED?
Are eight glasses a day — about 2 litres — enough? Should tea, coffee and other caffeinated drinks be thought of as part of the recommended daily fluid intake? Are unsweetened fresh juices a nutrition-packed replacement for water? Are vegetable juices healthy?
Most of believe the more water we drink, the healthier we are, which is true for most people without kidney problems. Our need for water is second only to our need for air – water accounts for about 60% of the body’s weight and is needed to carry nutrients to cells, moisten tissue, cushion joints, regulate body temperature and flush out toxins.
SO HOW MUCH IS IT?
The truth is, we do not need eight glasses of water a day. There is no scientific evidence to show that you must drink this much — unless you are physically active or live or work in a hot environment.
Much like the human body, water is an essential component of all foods. About 20% of our daily fluid requirement comes from food, with the water content being well over 90% in foods like milk and yoghurt, and in some fruits and green vegetables, such as watermelon, cucumber, cabbage, lettuce and spinach.
Fruits like apples, grapes, oranges, pears and pineapple are 80% to 90% water, while beans and legumes (dals) have a water content ranging from 60% to 70%. Even dried fruits, seeds and nuts are 1% to 9% water. Butter and oils are the only water-free foods.
SHOULD I DRINK WATER WITH MEALS?
Yes. We’re often told not to drink water with meals because it dilutes stomach acids and interferes with digestion. The opposite is true.
Water aids digestion by liquefying food to help stomach acids break it down faster and increase nutrient absorption in the intestines.
Drinking water with meals also prevents bloating and improves digestive function by lubricating the intestines and smoothening bowel movement.
Drinking water during meals fills up the stomach too, which lowers the calories consumed. This is a major reason why most weight-loss programmes recommend drinking lots of water through the day, especially before and during a meal.
ARE FRUIT JUICES HEALTHY?
No. Unsweetened fresh juices are not a nutritional substitute for water because they pack a lot of sugar and calories in each glass. While fresh fruit juices do have vitamins, minerals and other nutrients, they also have very high amounts of fruit sugars, which the World Health Organisation puts in the same category as harmful free sugars, the intake of which should not exceed 50 gm a day.
A glass of fresh orange juice, for example, has 0.4 gm of fibre and 24 gm of sugar, compared to 1.5 gm of fibre and 10 gm of sugar in one whole orange. The sugar in a glass of fresh, unsweetened orange juice (24 gm) is almost the same as in a glass of the much-maligned colas (26 gm), which is why fruits must only be had whole. Daily sugars must not exceed 25 gm a day, and with most of it coming from natural foods — such as milk (12.5 gm) and whole fruit (10-20 gm) — fresh juices must be sacrificed to cut back on calories.
WHAT ABOUT COCONUT WATER?
Coconut water is considered a super fluid because it contains potassium, which helps fight dehydration by increasing your body’s ability to absorb and retain water. It’s particularly useful to hydrate people who are ill or very active. But since a 250 ml glass contains 50 calories, using it as a water substitute will add to bodyweight.
Beetroot juice is rich in nitrates that relax blood vessels and lower blood pressure, but it’s also high in natural sugars. Super juices made from wheatgrass, cucumber, carrot and other superfoods don’t bring added benefits, so you’re better off munching on a carrot or cucumber.
HOW MUCH FLUID DO I NEED?
In a tropical country like India, you need to stay hydrated to beat the heat. Drink at least a glass of water when you get up and before you go to bed, have it with meals and before, during and after exercising or working in a hot and sweaty environment. The tea, coffee, milk, yoghurt and whole foods you have will also help meet your hydration target.
Dry and scaly skin, frequent muscle cramps and constipation are signs that your fluid intake may be suboptimal. Babies, children and people over 65 are at higher risk of dehydration than healthy people, as are those who are ill, fasting or dieting, because electrolyte imbalances make the body lose water faster. So they need to be extra-careful.