The amount of water you need changes with age. Our needs decrease compared to our weight. Therefore, newborn babies have a higher need for water (per kilogram of body weight) than their parents, and older adults have lower water needs than young adults.
Fluid requirements are related to metabolic needs and vary from person to person. Normal water turnover in adults is about 4% of total body weight per day. For example, if he weighs 70 kg, he loses about 2.5-3 liters of water per day (excluding sweating). This means that you need to consume that amount of water from food and drink to stay hydrated.
8 cups (or 2 liters) of water a day is often mentioned as the amount of water you should aim for and is a good way to track your intake. However, individual differences based on age, gender, size, and activity level are not taken into account.
Alcohol has a diuretic effect. In other words, it dehydrates the body by promoting water loss through urine. This fluid loss is an important factor contributing to the severity of a hangover. Always have a glass of water between alcoholic beverages to help you stay hydrated.
Caffeinated drinks (such as tea and coffee) have only a mild diuretic effect. For most healthy adults, up to 400 mg of caffeine per day is fine. This is equivalent to 4 cups of coffee or 8 cups of tea. Drinking more than this can affect your hydration levels.
Check Australian guidelines for fluid intake to see specific requirements.
If you’re not drinking enough and/or don’t like plain water, here are 10 ideas for staying hydrated this summer…