The major constituent of our bodies is water, and we need plenty of water passing through our systems to keep us healthy. Man can only survive a few days without water whereas he can last for months without food. Tap water also supplies minerals and trace elements. Coronary heart disease is less prevalent in hard water areas but the factor responsible remains a mystery.

Man prefers to flavour his water. Tea, coffee and cocoa have been used for centuries to provide hot beverages. The caffeine which they contain has a slight stimulatory effect on metabolism and withdrawal symptoms can occur in people who give up taking coffee after habitually drinking large amounts. Neither coffee nor tea provide energy unlike the modern squash, cordials and carbonated drinks. Low energy versions are now available and are better than drinking useless energy. Mixers can provide more energy than the alcoholic beverage to which they are added.

Several drinks have positive nutritional value. Milk is nearly a complete food and people drink significant amounts in tea and coffee. People on diets are advised to use skimmed milk which has similar nutritional value but half the energy. Fruit juices provide vitamin C, beers and malted drinks give B vitamins, cocoa powder and red wine provide iron.

Alcoholic beverages stimulate the palate and dry varieties provide less energy than sweet ones. Alcohol is metabolised at a slow rate by the liver so high intakes build up in the bloodstream and cause intoxication. Alcohol consumed with food has a less dramatic effect than alcohol on an empty stomach as it is absorbed more slowly.