Protein in the original Greek means "of first importance." The Greeks had it right! Proteincomplex chains of amino acids-is the basic building block of life and essential to almost every chemical reaction in the human body.
Food rich in protein includes meat, fish, fowl, eggs-most of which contain almost no carbohydrates-and cheese, nuts, and seeds. Many vegetables are also well supplied, but unlike animal foods, don't contain all the essential amino acids.
Fat provides glycerol and essential fatty acids, which the body cannot make. Fat is found in meat, fish, fowl, dairy products and the oils derived from nuts and seeds and a few vegetables such as avocados. Oils extracted from these foods represent one hundred percent fat and contain no carbohydrates.
Carbohydrate includes sugars and starches that are chains of sugar molecules. Although carbohydrate provides the quickest source of energy, we eat much more of it, by far, than our body needs to be healthy. Vegetables do contain some carbohydrates, but they also contain a wide and wondrous variety of vitamins and minerals. However, you can eat plenty of vegetables with high concentrations of beneficial nutrients and still control your carbs. On the other hand, carbohydrates such as those in sugar and white flour contain almost nothing that your body needs in large quantities.