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.

WHAT ARE THE MAJOR HEALTH ISSUES IN THE WORLD TODAY?

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.

HOW DOES LIFESTYLE AFFECT HEALTH?

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.

LIFE EXPECTANCY

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.

Table 20. THE TOP FIVE COUNTRIES

Japan 74.5 years
Australia 73.2 years
France 73.1 years
Sweden 73 years
Spain 72.8 years

Table 21. THE BOTTOM FIVE COUNTRIES

Botswana 32.3 years
Zambia 30.3 years
Malawi 29.4 years
Niger 29.1 years
Sierra Leone 25.9 years

NUTRITION

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.

WHAT IS A BALANCED DIET?

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.

FOOD PYRAMID

The food pyramid shows the proportions and range of food types that make up a healthy diet. It is important to eat plenty of fresh fruit and vegetables and to reduce the intake of saturated fats and sugar.

WHAT IS MALNUTRITION?

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.

WHY IS OBESITY A PROBLEM?

Obesity is increasingly common in wealthy countries. It can lead to medical problems, including diabetes, heart disease, stroke, and high blood pressure. Excess weight can also put strain on the body, causing back pain, shortness of breath, and arthritis.

FIND OUT MORE

Cells
Disease
Genetics

Copyright © 2007 Dorling Kindersley