Fats are large organic molecules constructed of glycerol and fatty acids. The simplest form is a triglyceride consisting of 1 glycerol and 3 (tri-) fatty acids. Fats contain many calories because they are large molecules and calories are released as the chemical bonds in the fat molecule are broken.

Cholesterol.
A substance in animal tissue that is an essential component of cell membranes and nerve fiber insulation. Cholesterol is important for the metabolism and transport of fatty acids and in the production of hormones and Vitamin D. Cholesterol is manufactured by the liver, and is also present in certain foods (e.g., eggs, shellfish). There are 2 types of cholesterol in the blood, high-density (HDL) and low-density (LDL) lipoproteins. Very low cholesterol levels may indicate malnutrition. Low-density lipoprotein (LDL) cholesterol provides cholesterol for necessary body functions, but in excessive amounts it tends to accumulate in artery walls; known as "bad" cholesterol. High-density lipoprotein (HDL) cholesterol, known as the "good" cholesterol; a high level in the blood is thought to lower the risk of coronary artery disease

Saturated fat.
Animal meats, butter, whole milk, and some tropical plant oils, such as palm and coconut, are the main sources of saturated fat, which is the least healthy type of fat. Saturated fat raises the level of LDL (bad) cholesterol, which causes numerous health problems if consumed in large quantities. Most saturated fats are solid at room temperature.

Unsaturated fat.
Most animal and vegetable fats contain monounsaturated fat, but in varying quantities. It is usually in liquid form at room temperature, but it may begin to solidify if it is chilled. Monounsaturated fat is the most desirable type of fat in the diet because it helps to decrease the LDL (bad) cholesterol in the blood and helps to increase the HDL (good) cholesterol. Good sources of monounsaturated fat are olive oil, canola oil, peanut oil, and most nuts. Olive oil has the highest percentage (about 77%) of monounsaturated fat of any edible oil.

The main sources of polyunsaturated fats are seeds, nuts, grains, and vegetables. Polyunsaturated fat is usually in a liquid state at room temperature and also when chilled. It lowers the overall cholesterol level, but it also reduces HDL or good cholesterol. Recommended daily allowances of polyunsaturated fats should be part of a balanced diet, but some tests have shown that high consumption may actually be damaging to the digestion and nervous systems, so moderation is the key for a balanced and healthy diet.

Trans-fat.
Trans-fatty acid, also known as trans-fat, is formed when hydrogen is added to vegetable oil in order to change the liquid oil into a solid at room temperature. This process is known as hydrogenation, which also transforms the unsaturated fats of the liquid oils into saturated fat. Like saturated fat, trans-fat may raise blood cholesterol levels and increase the risk of heart related diseases. Many shortenings, margarine, and commercially baked goods are high in trans-

Back to top