Healthy and Unhealthy - The Kinds of Fat
Saturation means that all the places for hydrogen bonds along the carbon chains that make the fatty acid chains in the fat are full. That makes the fat more stable. Saturated fats are hard at room temperature and doesn't breakdown as easily in cooking, which is one of its benefits.
Sources of saturated fat: red meat, dairy products such as whole milk, cheese and butter; oils such as coconut oil, palm kernel oil and palm oil.
The conventional battle cry of dietary fitness has been to stay away from saturated fat. They raise LDL cholesterol levels and have been associated with heart disease, cancer and other diseases of inflammation. Everything, however, has its place and small amounts of saturated fat do have benefits to offer.
Saturated fats can provide vitamins and minerals. Studies show they help transport calcium to the bones, and they have a role in supporting the immune system. The brain also uses saturated fat, including cholesterol.
The saturated fats also help the body use and move unsaturated fat. The way different fats help breakdown and move other fats has implications for weight loss that are not fully understood but clearly put the need for balancing ones attitude toward fat in the forefront. Coconut oil, for example is a saturated fat that is gaining a reputation as a possibly healthful fat that may help stimulate the metabolism.
We don't need a lot of saturated fat. The U.S.D.A 2010 Dietary Guidelines suggest that for a healthful diet, saturated fat should be about 7% of the total calories you eat. That's not much.
Unsaturated fat is divided into two categories polyunsaturated and monounsaturated. Monounsaturated fats have one carbon bond that does not have a hydrogen molecule attached. Polyunsaturated fats have more than one bond for a hydrogen atom that is unfilled. Unsaturated fats are usually liquid, even when cool, so we call them oils, and they are less stable than saturated fats.
Both mono and polyunsaturated fats are generally considered healthy fats, with monounsaturated fat being the most healthy. Monounsaturated fat is associated with lowering bad cholesterol (LDL) and raising good (HDL).
Sources of monounsaturated fats: olive oil, high-oleic sunflower oil and safflower oil, canola oil avocado, almond, peanut corn, sesame soy and cod liver oil
Sources of polyunsaturated fats: cold water fish like salmon, walnuts, seeds, dark leafy greens, and flax oil.
Technically, trans fats are unsaturated fats, but they have been chemically altered by industry to have an extra hydrogen atom attached to them. Thus they are "partially hydrogenated". Unsaturated fats tend to be unstable, partial hydrogenation makes them more stable and that means they have a longer shelf life. That is good for the packaged food maker or a grocery store, but it's bad for you. Trans fats raise bad cholesterol, which clogs arteries and lower good cholesterol, which helps our bodies make sex and steroid hormones and contributes to cell flexibility. The F.D.A requires that trans fats be labeled in foods. Read the labels. If says trans fats, stay away. Remember, a partially hydrogenated fat is a trans fat.