Nutrition :: Introduction
Proper nutrition is powerful and good to those people who are well nourished, likely to be healthy, productive and able to learn. Good nutrition benefits families, their communities and the world as a whole. Healthy diets contain the amounts of essential nutrients and calories needed to prevent nutritional deficiencies and excesses. Healthy diets also provide the right balance of carbohydrate, fat, and protein to reduce risks for chronic diseases, and are a part of a full and productive lifestyle. Such diets are obtained from a variety of foods that are available, affordable, and enjoyable.
Man needs a wide range of nutrients to perform various functions in the body and lead a healthy life. The nutrients include proteins, fat, carbohydrate, vitamins, minerals and water. These nutrients are chemical substances which are present in the food we eat daily. The foods containing these nutrients which we consume daily are classified as cereals, legumes (pulses), nuts and oilseeds, vegetables, fruits, milk and milk products and flesh foods (fish, meat and poultry). Protein, fat and carbohydrates are sometimes referred to as proximate principles. They are oxidized in the body to yield energy which the body needs. Vitamins and minerals do not supply energy but they play an important role in the regulation of the metabolic activity in the body and help in the utilization of the proximate principles.
The Dietary Guidelines are designed to choose diets that will meet nutrient requirements, promote health, support active lives, and reduce chronic disease risks. Certain diets raise risks for chronic diseases. Such diets are high in fat, saturated fat, cholesterol and salt and they contain more calories than the body uses. They are also low in grain products, vegetables, fruit, and fiber.
People require energy and certain other essential nutrients. These nutrients are essential because the body cannot make them and must obtain them from food. Essential nutrients include vitamins, minerals, certain amino acids, and certain fatty acids. Foods also contain other components such as fiber that are important for health. Although each of these food components has a specific function in the body, all of them together are required for overall health. People need calcium to build and maintain strong bones, for example, but many other nutrients also are involved.
The carbohydrates, fats, and proteins in food supply energy, is measured in calories. Carbohydrates and proteins provide about 4 calories per gram. Fat contributes more than twice as much as about 9 calories per gram. Alcohol, although not a nutrient, also supplies energy about 7 calories per gram. Foods that are high in fat are also high in calories. However, many low fat or non-fat foods can also be high in calories.
Many genetic, environmental, behavioral and cultural factors can affect a person's health. Understanding family history of disease or risk factors, such as body weight and fat distribution, blood pressure and blood cholesterol, can help people make more informed decisions about how to improve health. Making good food choices is among the most pleasurable and effective ways of improving health.
Healthful diets help children to grow, develop and perform well in school. A healthy diet allows adults to work productively and feel their best. Good food choices also can help to prevent chronic diseases, such as heart disease, certain cancers, diabetes, stroke and osteoporosis, that are leading causes of death and disability. A proper diet can also reduce major risk factors for chronic diseases, such as obesity, high blood pressure and high blood cholesterol.
Healthful diets contain the amounts of essential nutrients and energy needed to prevent nutritional deficiencies and excesses. Healthful diets also provide the right balance of carbohydrate, fat and protein to reduce risks for chronic diseases, and these diets can be achieved through a variety of foods that are available, affordable and enjoyable.
An individual's food choices depend on energy needs, nutrient needs and enjoyment.