Maggie Greenwood-Robinson - Good Fat vs. Bad Fat

Fats.

Theyre the black-hatted bad guys of nutrition, the most demonized of all nutrients. Even the word fat itself conjures up all sorts of negative associations when used in everyday language. Take the expressions fathead, fat chance, fat cat, and fatso, for example. Fat is practically a four-letter word.

But is fat really all that bad? Does it deserve to be so maligned?

This may come as a surprise to you, but fats are mostly good guys in nutrition. You need them to survive. In fact, there are a slew of good fats with astonishing powers to outwit disease and keep you healthy for a lifetime. Sure, there are some health-risky fats, but even some of those are needed in small amounts for good health. When youre dealing with fats, the key is to control not only the amount you eat but also the kind of fat you eat.

To get a handle on how fats affect your health, it helps to learn some basic facts about this most misunderstood of all nutrients. So lets get started on a short nutrition lesson.

Youve heard the old expression, Oil and water dont mix. Well, fatsmany of which are oilsare members of a family of chemical compounds technically known as lipids that for the most part dont dissolve in water. You know this if youve ever made salad dressing and watched the fatty part separate from the rest of the liquid and gradually rise to the top.

When we speak of fat in our foods or on our bodies, were talking about triglycerides. Triglycerides make up about 95 percent of dietary fat and 90 percent of body fat. Some triglycerides also circulate in your bloodstream. Chemically, a triglyceride is a backbone of glycerol (a type of alcohol) to which three fatty acids are attached, hence the name triglyceride.

A fatty acid is a building block of fat. Many specific types of fatty acids are found in various fats, each with different properties that influence your health in far-reaching ways. Fatty acids are contructed of chains of carbon atoms with hydrogen atoms attached, with an acid group at one end. Think of this configuration as a charm bracelet. The carbons form the chain, and the hydrogen and the acid group are the charms.

The lengths of these chains vary according to the fat. Fats found in meat, for example, usually have chains that are sixteen or more carbons long. Some carbon chains are much shorter, with six, eight, ten, or twelve carbon atoms.

Is the length of a fat chain important?

Yes. Heres the deal: Length has a lot to do with how your body uses the fat and obtains energy from it. Short-and medium-chain fatty acids, which are generally found in butter and coconut oil, are a good example. During digestion, they are absorbed more readily by your body than longer-chain fatty acids are and thus supply quick energy. Because of this, short- and medium-chain fatty acids are less likely to be packed away as body fat. Longer-chain fatty acids, on the other hand, tend to be stored as fat. So to a certain extent, length matters.

Fatty acids from food are chemically classified not only by the length of their chains but also according to the number of hydrogens the fatty acid chain holds. This attribute is referred to as saturation.

When a fatty acid carries the maximum number of hydrogen atoms, it is said to be loaded or saturated. If there are one or more places in the chain where hydrogens are missing, the fatty acid is unsaturated. A fatty acid with a single point of unsaturation is termed monounsaturated; a fatty acid with two or more points is called polyunsaturated.

The degree of saturation affects the temperature at which the fat melts. Generally speaking, the more saturated the fatty acids of a fat are, the more solid the fat is at room temperature. Examples of saturated fats include those found in beef, butter, lard, and dairy products. Unsaturated fats such as vegetable oils are usually liquid at room temperature. An exception to the rule that saturated fats are more solid than unsaturated fats is coconut oil, a saturated fat that is liquid at room temperature.