Too much fat is definitely not your friend.

Too much fat is definitely not your friend.

Popular consensus to the contrary, the body does need some fat, especially up to the age of two. After that, the requirement is drastically reduced. However, most Americans continue the high-fat diet well beyond the age of two, many wells into their seventies, which is a little excessive.

Still, throughout life, fat is essential to provide energy and support growth. Fat is, in fact, the most concentrated source of energy available to the body. The point is that after the age of two, the body only requires small amounts of it, while we normally simply pile it on.

It is an established medical fact that excessive fat intake is a major causative factor in obesity, high blood pressure, coronary heart disease, and colon cancer. Too much fat is definitely not your friend.

What is fat?

Whereas proteins are built from amino acids, fat is built from fatty acids. There are four kinds of them:

Saturated
Polyunsaturated
Monounsaturated
Trans

These classifications are based upon the number of hydrogen atoms present in the chemical structure of a given molecule of fatty acid.

Saturated Fatty Acids are found primarily in animal products, including dairy foods such as whole mile, cream, and cheese, and in fatty meats like beef, veal, lamb, pork, and ham. The fat marbling that you can see in beef and pork is composed of saturated fat. What is left in the frying pan after you’ve finished preparing your crispy bacon is saturated fat. Some vegetable products, including coconut oil, palm kernel oil, and vegetable shortening, are also high in saturated fats.

The liver uses saturated fats to manufacture cholesterol. Therefore, excessive dietary intake of saturated fats can significantly raise the blood cholesterol level, especially the level of LDLs, low-density lipoproteins (a protein that carrier lipid, or fats, in the bloodstream), what’s known as “bad” cholesterol. HDLs, or high-density lipoproteins, on the other hand, are considered “good” cholesterol because they carry unneeded cholesterol away from the cells and back to the liver, where it is broken down for removal from the body.

Guidelines issued by the National Cholesterol Education Program (NCEP), and widely supported by most experts, recommend that the daily intake of saturated fats be kept below 10 percent of daily caloric intake. However, for people who have severe problems with high cholesterol, even 10 percent may be too much. As an aside, the average American saturated fat intake, as a percentage of total calories, unfortunately, ranges in the high 20s and low 30s.

Polyunsaturated Fatty Acids are found in greatest abundance in corn, soybeans, safflower, and sunflower oils. Certain fish oils are also high in polyunsaturated fatty acids. Unlike saturated fats, polyunsaturated fats may actually lower your blood cholesterol. In the process, however, large amounts of polyunsaturated fats have a tendency to deplete your HDLs, and for this reason, and because like all fats, polyunsaturated fats are high in calories for their weight, the NCEP suggests that an individual’s intake polyunsaturated fats should not exceed 10 percent of total calorie intake.

Monounsaturated Fatty Acids are found in vegetable and nut oils such as olive, peanut, and canola. These fats appear to reduce blood levels of LDLs without affecting HDLs. However, this positive impact on LDLs is quite modest, and the NCEP suggests that we keep monounsaturated fats below 15 percent of total caloric intake.

Trans-Fatty Acids or trans fats occur when polyunsaturated fats are altered through hydrogenation, a process used to harden liquid vegetable oils into solids like margarine and shortening. One recent study found that trans-monounsaturated fats raised LDL levels, behaving pretty much like saturated fats.

Bottom line: Polyunsaturated and Monounsaturated fats are more desirable than saturated fats. But, keep in mind, that our total calories from all four kinds of fats should not exceed 20 to 25 percent of total calorie intake.