How many litres a day? Do tea and coffee count? The truth about detox waters.
Water makes up more than half of our body weight and plays a role in many functions from digestion to temperature regulation. Even so, many myths circulate about water intake. Let us look at the most common ones.
How many litres should I drink a day?
There is no single number for everyone. As a general starting point about 30-35 ml per kilogram is suggested (2.1-2.5 litres for 70 kg), part of which comes from food. Needs rise in hot weather, exercise, pregnancy and breastfeeding. Light yellow urine is a practical sign of adequate hydration.
Myth 1: 'Tea and coffee do not count, they even dehydrate'
Moderate amounts of tea and coffee (about 3-4 cups of coffee a day, up to 400 mg of caffeine) contribute to total fluid intake. However, the caffeine limit is lower in pregnancy and your doctor's advice should be followed. Sugary or milky tea and coffee drinks add extra calories.
Myth 2: 'Drinking water makes you lose weight'
Drinking water before meals can increase fullness in some people and reduce portions. But water alone does not burn fat. Drinking water instead of sugary drinks markedly lowers calorie intake.
Myth 3: 'Drinking water with meals spoils digestion'
Scientific evidence does not show that drinking a reasonable amount of water with meals spoils digestion. For people with reflux complaints, not drinking large amounts of fluid during meals may be comforting.
Myth 4: 'Detox water cleanses the body'
The liver and kidneys are the body's natural cleansing systems. Lemon or cucumber water can be pleasant for flavour, but the promise of 'flushing toxins' lacks scientific basis.
To increase your water habit
- Start with a glass of water when you wake up
- Carry a 500 ml bottle on your desk or in your bag
- Put a glass of water before each meal
- Add mint, lemon or cucumber for flavour
- Use smartphone reminders
Caution
In kidney failure, heart failure and with some medications, fluid amounts may be limited by a doctor. Drinking excessive amounts of water can also rarely be dangerous; get doctor or dietitian approval for your target.