DK Human Body: Health
Being healthy means being free of disease or injury and able to lead a fulfilling, active life. Many factors contribute to a person’s health, including genes, the environment, NUTRITION, lifestyle, and luck.
In poor countries, dirty water and lack of adequate food are among the main causes of poor health. Infectious diseases such as malaria and AIDS are also major problems, especially in countries that cannot afford modern drugs and medical equipment. In rich countries, health problems are more often caused by people’s lifestyle.
The affluent lifestyle of people in rich countries can increase the risk of serious diseases. Heart disease, obesity (excessive storage of fat), and strokes (blood clots in the brain) are all more common in people who do little exercise or eat too much rich food. Health problems caused by tobacco, alcohol, and drug abuse are also common in rich countries.
These World Health Organization figures show average life expectancy for babies born in 1999. The life expectancy of people living in the wealthy countries of the world is almost three times that of people in the poorest.
The process of supplying the body with the nutrients (foods) it needs to stay alive is called nutrition. Eating a variety of foods—a balanced diet—is an important part of keeping healthy.
A balanced diet includes a mixture of carbohydrates, proteins, fats, vitamins, minerals, and fiber. Sweets and fast foods usually contain too much carbohydrate and fat, and little of the fiber needed to keep the digestive system healthy. Fast food that does not contain fresh ingredients is often low in vitamins and minerals.
Malnutrition means “bad nutrition.” This can happen when a person has too little of certain types of food. Lack of protein, for example, can cause stunted growth. Malnutrition can also occur if the diet has excessive amounts of some types of foods—too much fat and sugar, for example, can result in obesity.
