A fat molecule contains carbon atoms bonded to other carbon atoms; the number of carbons in the chain varies by the specific fat. Fats are grouped into types depending on how many of those carbon atoms bond with a pair of hydrogen atoms.
Saturated fats: it isn’t really saturated fats that are bad for you – it’s what happens to those fats during processing, cooking, and metabolism. In fact, some saturated fats actually help prevent those conditions and are essential to good health.
There are twelve kinds of saturated fats, most of them known as long-chain fatty acids because of their long (about 20 atoms) carbon chains. Saturated fats in meat are long-chain, and they don’t break down easily unless heated, so the body can’t make good use of them as fuel. And when long-chain saturated fats are heated enough to break down, either during processing or cooking, trans fats are formed.
Trans fats: raise cholesterol levels, impair circulation, and increase the risk of man degenerative diseases and age-related maladies. Trans fats are officially known as trans-fatty acids, which should give you a clue right there that they should have no place in your diet. With no redeeming qualities, trans fat is the one type of fat you must avoid altogether.
Monounsaturated fat: one of the wonderful properties of monounsaturated fats (besides their ability to cleanse the body of acids and fuel your metabolism) is that they are very stable. That makes them the best choice when you cook your food. The oils in olives and avocados are monounsaturated.
Polyunsaturated fat: electron-rich polyunsaturated fats can bind to more excess acids in the body than any other type of fat, and they are the best fuel for the body to use to generate energy. These fats will help you lower your cholesterol levels because they buffer acids in your body, so less cholesterol is produced. In addition, the fats that are crucial in forming cell wall membranes are mainly polyunsaturated fats. Polyunsaturated fats should make up to 20 to 40 percent of your caloric intake – at least 60 to 90 grams of the stuff each day, for most people.