To achieve a healthful diet you must eat the proper balance of different kinds of foods so that your body has the raw materials it requires to build, maintain, and repair its basic units, the cells. You also need to eat the right amount of food so that you have enough energy to power your daily activities without having too much or too little stored as fat.
Energy is measured in units called calories. A calorie is the amount of energy required to raise the temperature of one gram of water 1° Celsius. In scientific literature, energy is usually reported in kilo calories, and one kilo calorie equals 1000 calories of energy. However in physiology, the prefix kilo is dropped, and a kilo calorie is referred to as a Calorie(with a capital C).
Nutrients are substances found in food that provide the energy or structural materials required for normal growth, maintenance, and repair. These include
Nutritionists have devised a set of general guidelines to help determine whether you are achieving the right balance of nutrients. These guidelines are based on six different food groups:
(1) milk and dairy products
(5) breads, cereals, and grains
(6) fats, oils, and sweets
These food groups are arranged as a pyramid. The amount of space allocated for each group represents the relative amount of your diet they should comprise. The largest is taken up by breads, cereals, and grains, which are rich in carbohydrates.