Nutrition: an overview
Our body needs to be provided regularly with a certain amount of nutrients in order to function. In order to provide her with these nutrients, we need to eat a balanced diet. A healthy diet allows us to maintain the body's mechanisms allowing us to perform challenging physical and mental activities and stay healthy.
Everyone has different calorie intakes which will likely vary from day to day. But it is necessary to provide our bodies with what it needs to function. To this end, governments, universities, and health centers around the world have developed nutritional guides and food pyramids to help the public understand the principles of nutrition and healthy eating.
What are the components of a balanced diet?
Although many nutrients can be made by the body, some, especially essential nutrients, cannot. Therefore, we must provide it to our bodies through our diet - what we eat and drink.
Essential nutrients include 9 of the 20 amino acids found in proteins, some fatty acids found in oils and fats, and a number of minerals and vitamins. In general, there are two categories of nutrients: macronutrients and micronutrients.
Doctors and nutritionists recommend other substances, such as fiber, to improve intestinal motility, reduce fluctuations in sugar and cholesterol levels after meals, and promote the elimination of carcinogens (cancer-causing substances) produced by bacteria in the large intestine.
Macronutrients include fats, proteins, carbohydrates, and some minerals. Our body needs it daily in large quantities. They make up the bulk of our diet, and provide our bodies with the energy and building blocks it needs to grow, perform various activities, and maintain itself. Once these foods are digested, they are broken down into their basic units, which are sugars from carbohydrates, fatty acids and glycerol from fats and amino acids from proteins. The energy content of each food is measured in calories.
Individual calorie intake varies widely with physical activity, age, gender, and availability. In general, the following is the average recommended caloric intake: For the elderly, children and irregular women, about 1,600 calories per day; For active women, older children, and men who do not exercise, about 2,000 calories per day; Young adults and teens have about 2,400 calories per day.
Major minerals include calcium, phosphorous, sodium, chloride, potassium, and magnesium. Our body needs about 1 to 2 grams of each of these elements every day. Water is another macronutrient that we need 1 ml for for every kilocalorie of energy we expend, that's 2500 ml (2.5 liters) per day.
Essential fatty acids include linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid. Linoleic acid and linolenic acid are found in vegetable oils. Eicosapentaenoic acid and docosahexaenoic acid are essential for brain development and are present in fish oils.
Micronutrients include vitamins and trace minerals, which are the elements the body needs to metabolize macronutrients. Only a small amount of micronutrients, milligrams or micrograms, is needed. Some of the essential trace minerals include iron, zinc, copper, manganese, molybdenum, selenium, iodide, and fluoride. Except for the latter, all of these minerals activate enzymes that help our bodies metabolize food.