Plain water is highly recommended for daily fluid intake. Proper hydration is vital for good health and well-being. Poor hydration can affect one’s mood, concentration and performance negatively, and has recently also been linked to an increased risk of chronic diseases. Drinking enough water also helps produce more urine, which helps to flush out infection-causing bacteria.
What should we drink every day?
Fluid intake in healthy human beings is regulated by thirst. Water is an essential nutrient for life and is considered the ideal drink to quench thirst and ensure hydration. Ironically, it is often ignored in dietary recommendations.
Drinking plain water (H2O) helps the body flush the kidneys and liver without having first to process out any additives it. This makes water the ideal drink first thing in the morning and last drink at night. Despite the benefits of plain water, many people prefer other drinks such as cool drink, fruit juice, coffee, tea, milk or sport drinks. These beverages could contribute to the daily energy intake.
The USA’s National Research Council (NRC) recommends a daily H2O intake of about 1ml/kcal energy expenditure, which translates to about 8 glasses of water per day. This recommendation is based on an average-weight (70 kg) male . However, no single formula fits every individual or every situation, since water intake recommendations also depend on other factors such as activity, humidity, climate, body temperature and body composition.
Water forms part of every cell in the body. Comprising on average 50% of a woman’s body weight and 60% of that of a man. Every system and function in the body depends on water. H2O for example, helps with the digestion of food, carries nutrients to cells, and provides a moist environment for ear, nose and throat tissues.
The amount of fluid consumed each day should be equivalent to approximately the amount lost.
Mild dehydration affects a wide range of cardiovascular and thermo-regulation processes and responses. Dehydration of 3-5% of body weight decreases physical strength and performance, and is the primary cause of heat exhaustion. Water losses from the lungs and skin (500ml – 1 litre/day) are responsible for approximately half of the daily turnover. And losses from stools and urine account for the rest of the daily losses. Yet, despite changes in body composition, function and the environment, most healthy people manage to regulate their daily water balance well across their lifespan.
Why is water the best possible choice?
Water is highly recommended for daily fluid intake. Some studies have shown that plain water consumption is associated with better diets, better health behaviours, and a lower burden of chronic disease. It provides no additional energy, which makes it ideal for overweight or inactive adults. It also provides variable amounts of minerals such as calcium, magnesium and fluoride, depending on its source.
Despite plain H2O fulfilling almost all the fluid needs of healthy adults. In most developed Western societies, diets provide an excess of total energy, which is associated with obesity and so-called lifestyle diseases.
Obesity and overweight are mainly caused by an imbalance between energy consumed and energy expended:
- an increased intake of energy-dense foods that are high in fat or added sugars; and
- a decrease in physical activity due to the increasingly sedentary nature of many forms of work, changing modes of transportation, and increasing urbanisation/development.
South African adolescents and learners are at an increased risk for environmental factors that cause obesity. For example, they are more likely to consume sugar-sweetened drinks, they are less likely to compensate for “fast food” energy, and they generally consume more energy-density foods (e.g. sweets, chocolate, and chips).
South Africa has a heavy burden of infectious diseases (such as HIV/AIDS and tuberculosis). These exist alongside diseases of lifestyle (non-communicable diseases) such as under-nutrition, over-nutrition, diabetes, hypertension and cancer. Diet-related non-communicable diseases account for 28% of the total burden of disease in South Africa. Specific dietary and lifestyle changes have been observed in the consumption of alcohol, tobacco and food – particularly a shift to a diet high in sugar, salt and saturated fat – along with the reduction in physical activity.
Recommendations for South Africans
- Water fulfills almost all the fluid needs of healthy adults.
- Women should drink at least 4 (250ml) glasses and men at least 6 glasses of clean, safe water per day.
- Children should drink water when thirsty and limit their intake of milk and fruit juice.
- Drinks should not contribute to more than 14% of total daily energy intake.
- Schools should encourage children to meet their fluid needs with water. By providing clean, safe water, and limiting the availability of other cool drinks/juices.
- Sweetened cool drinks (including carbonated cool drinks) should be limited. Ad avoided by diabetics and inactive and/or overweight adults and children.
- Fruit and vegetable juices (100% juices) and sports drinks should be limited to no more than one standard cup per day.