Fats or Lipids
The largest puzzle piece belongs to fats or lipids. When animals consume more energy than they can use, the surplus is stored as fat. Fat is a very concentrated source of energy: a gram of sugar brings 4 calories with it; a gram of fat brings 9 calories, more than double that of sugar. Fats are often thought of as being the “bad guys” of the nutrition world, taking the blame for everything from acne to ulcers. But not all fats are created equal. The real “bad guys” are saturated fats. A diet high in saturated fats may increase your risk of developing heart disease and cancer. The “good guys” are vegetable fats such as olive and safflower oil. These oils may decrease your risk of developing heart disease. But the real heroes in this story are the omega-3 fatty acids. This is a type of oil found in cold-water fatty fish such as mackerel, herring, and salmon. Omega-3 fatty acids can decrease the risk of heart attack by making your blood platelets less sticky. They can also reduce Inflammation caused by autoimmune diseases such as rheumatoid arthritis. All fats, however, have one thing In common: They cause weight gain when eaten in excess.
With the addition of protein, our nutrition puzzle begins to take shape. The word protein comes from the Greek word meaning “to take first place.” After water, protein is the most plentiful substance in our body; it is an integral part of every living cell. In foods, protein usually comes packaged with fat, and the type of fat determines how “healthy” a protein source is. Red meat contains a lot of saturated fat along with its protein. Fish contains a lot of omega-3 fatty acids. Beans and legumes are excellent low-fat sources of protein when balanced with nuts, seeds, and grains.
Our nutrition puzzle would not be complete without minerals. The word mineral means an element in its simple inorganic form. In the body, minerals occur chiefly in their ionic form; metals form positive Ions (cations) and nonmetals form negative Ions (anions). Minerals can be used for structural tissues, as calcium and magnesium are used in bone, or they may be used in electrolyte balance, as is the case with potassium, sodium, chloride, and calcium. The major minerals are calcium, phosphorus, chloride, magnesium, potassium, sulfur, and sodium. Minerals needed only in tiny amounts are called trace minerals. They include arsenic, chromium, cobalt, copper, fluoride, nickel, selenium, manganese, boron, and vanadium.
The tiniest part of our puzzle belongs to vitamins. Vitamins are substances that are needed by the body for normal growth and tissue maintenance. Even though they are needed in only small amounts, most vitamins must be supplied by the diet because the body cannot manufacture them. They are usually divided into two groups: the water-soluble vitamins and the fat-soluble vitamins. The water-soluble vitamins include the B-complex vitamins and vitamin C. The fat-soluble vitamins include vitamins A, D, E, and K. The body can store the fat-soluble vitamins, but water-soluble vitamins must constantly be replenished. Fruits and vegetables are excellent sources of many vitamins.