It's that time of year when the warm summer weather draws many families outdoors to enjoy healthy activities like a walk in the park, an afternoon at the beach or a hike through the wilderness. But unless we are careful, the heat can also lead to dehydration – a depletion of our body fluids.
Water makes up approximately two thirds of an adult's body weight, and is important to the body's core functions, such as regulating its temperature and lubricating joints. But our bodies naturally lose water everyday – for example when we perspire while exercising or due to the heat. Therefore, it is important to maintain fluid balance and avoid dehydration by regularly replenishing our bodies with liquid.
This is particularly important for infants, children, pregnant women and the elderly, as they are most vulnerable to dehydration.
Also, when we are ill and experience fevers and diarrhoea, our bodies lose excessive amounts of fluid and electrolytes. It is important to replenish those fluids with electrolyte solutions, some of which are described below.
Watch out for warning signs of dehydration, which include dry mouth and skin, tiredness, weakness, nausea, headaches, dizziness and confusion. Pay particular attention to these symptoms in young children and the elderly, who may not be aware that they are experiencing dehydration.
People's fluid intake requirements vary and depend on their environment, age and physical activity. The general recommendation is for adults to drink 6–8 glasses of fluids a day (equivalent to around three 500 millilitre water bottles). Keep in mind however, that our bodies need extra fluid in hot climates and when we engage in vigorous physical activities.
Sources of fluid
- Water is the best source of fluid; it is inexpensive and comes without hidden extras like additives or sugar.
- Tea and coffee are sources of water and contain some nutrients if consumed with milk. Tea also contains antioxidants. These drinks are fine in average amounts (around 3–4 cups a day); however, excessive consumption, especially of strong coffee, can lead to a high caffeine intake. Caffeine can act as a diuretic and cause the body to lose fluid.
- Fruit juices and smoothies provide vitamins (smoothies also provide some fibre) and can count once a day towards your daily fruit recommendation. But limit them to only one glass a day – ideally with meals – as they are high in sugar and can cause tooth decay.
- Milk provides water and is a rich source of nutrients like protein and calcium, which is important for our bone health. Choosing low-fat milk will save you from the additional fat and calories.
- Other sources of fluid include low-calorie soft drinks and some foods like soups, yoghurts, fruit and vegetables.
- Sport (isotonic) drinks can help in replenishing electrolytes as well as fluids, and may be useful for those exercising for long periods.
Quick tips to stay hydrated
- Keep a bottle of water handy at your desk, in the car and on the go.
- If you dislike plain water, try drinking a flavoured water or adding a slice of lemon.
- Try to avoid drinks that may contribute to dehydration, such as those with a high sugar or caffeine content.
- Try decaffeinated drinks like fruit teas.
- Choose low-calorie soft drinks or sugar-free squashes (cordials).
- Eat foods with a high water content like pears, apples and salads that count towards your daily portion of fruits and vegetables.
- Try drinking fluids at frequent intervals to help optimise hydration.
- Make drinking water a routine by setting a daily schedule. Consider using your computer or mobile device to set regular, helpful reminders.
- Remember to drink before and during physical activity, and more often when the weather is hot.
By making a conscious effort to drink enough fluid and to drink often (and encourage our family members to do the same) we can all stay well hydrated and enjoy the summer weather.