Fats, as a basic group of nutrients, are perhaps the most misunderstood of the body’s required energy sources. Fats play a vital role in maintaining healthy skin and hair, insulating body organs against shock, maintaining body temperature, and promoting healthy cell function. Fats make foods taste better and carry the fat-soluble vitamins A, D, E, and K to the cells. They also provide a concentrated form of energy in the absence of sufficient amounts of carbohydrates and make you feel full after eating. If fats perform all these functions, why are we constantly urged to cut back on them? Although moderate consumption of fats is essential to health, over consumption can be dangerous.
Triglycerides, which make up about 95 percent of total body fat, are the most common form of fat circulating in the blood. When we consume too many calories, the liver converts the excess into triglycerides, which are stored throughout our bodies. The remaining 5 percent of body fat is composed of substances such as cholesterol, which can accumulate on the inner walls of arteries and narrow the channels through which blood flows. This buildup is a major cause of atherosclerosis, a component of cardiovascular disease. The ratio of total cholesterol to a group of compounds called high-density lipoproteins (HDLs) is important to determining risk for heart disease. Lipoproteins facilitate the transport of cholesterol in the blood. High-density lipoproteins are capable of transporting more cholesterol than are low-density lipoproteins (LDLs). Whereas LDLs transport cholesterol to the body’s cells, HDLs apparently transport cholesterol away from the cells and to the liver, where they are being eliminated from the body.
People with a high percentage of HDL therefore, appear to be at lower risk for developing cholesterol-clogged arteries. Regular vigorous exercise plays a part in reducing cholesterol by increasing high-density lipoproteins.
