All fats are a mixture of saturated, monounsaturated and polyunsaturated fatty acids. Fatty acids may be thought of as the ‘building blocks’ of fat. They differ in the amount of hydrogen they contain. Saturated fatty acids contain the most hydrogen–they are ‘saturated’ with hydrogen. Polyunsaturated fatty acids contain the least amount of hydrogen.

Fats in foods contain both saturated and unsaturated fatty acids. In general, fats containing a majority of saturated fatty acids, such as lard and butter, are solid at room temperature.

Oils such as soybean, canola, cottonseed, corn and other vegetable oils, which are liquid at room temperature, are considered unsaturated fats.

Health professionals do not recommend that individuals eliminate all fat from their diets. Rather, they state that a person’s diet should contain no more than 30 percent of total calories from fat and less than 10 percent of calories from saturated fat. An easy rule of thumb is to choose foods that contain no more than 3 gm. of fat per 100 calories. 

Remember that nutrition is not an exact science. As more information is learned about the human body, new recommendations will constantly arise. What was true yesterday may not be true today or tomorrow, based upon new research information. We do know to choose a diet that is low in saturated fats. 

Reducing consumption of saturated fats and cholesterol is key to a heart-healthy diet, by avoiding fried foods and reduce your intake of butter, margarine, shortening and lard. In turn, increasing your intake of beneficial fats, such as extra virgin olive oil, and omega 3 rich foods, such as salmon and flaxseeds, can have a beneficial effect on your health. 

Learn which foods are and aren’t high in fat, then choose low-fat foods more often. Watch for hidden fat, especially in baked goods, snacks and other processed or prepared, packaged foods. We do know that cutting down on saturated fat in your diet can reduce the risk of heart disease by lowering your blood cholesterol. 

Foods that are high in cholesterol, such as eggs, liver and beef, raise your cholesterol and increase your risk of heart disease. So-called cholesterol-free foods that are high in saturated fats also can raise your cholesterol. 

Safest fats: For the record, the safest fats are monounsaturated ones such as olive and canola oils, which don't seem to increase the risk of heart disease, as well as the omega-3 fatty acids found in fish that actually seem to protect against heart attacks by thinning blood. They also act as anti-inflammatory agents and are important natural treatments for autoimmune disorders and arthritis. You can get adequate amounts of omega-3s by eating salmon, flaxseed or walnuts.

What is saturated fat? Saturated fat is a type of fat that is found in foods. Butter contains a high percentage of saturated fat and cholesterol. Vegetable-based margarine, vegetable shortening and vegetable oil have a lower percent of saturated fat. This type of fat may raise the body's total blood cholesterol level more than other types of fat. Most saturated fats are solid at room temperature. Some foods high in saturated fat include the following:

What is unsaturated fat? Unsaturated fat is a type of fat that is found in foods. This type of fat does not usually increase the body's total blood cholesterol level when eaten in moderate amounts. Some foods high in unsaturated fats include the following:

What is cholesterol? Cholesterol is a waxy substance that is made by the body and found in some foods. Cholesterol found in foods is called dietary cholesterol. Dietary cholesterol is found in animal foods such as the following:

Plant foods (grains, fruits, and vegetables) do not contain cholesterol. If the body's blood cholesterol gets too high, then cholesterol may build up in the heart and cause damage.

Trans fatty acids (TFAs) These little devils are produced when liquid oil is converted to a solid. The process is called hydrogenation. Trans-fatty acids are by-products of hydrogenation. Manufacturers do this to give baked goods a longer shelf life. Simply put, solid shortenings stay fresh longer than liquid oils. So cookies, cakes and crackers as well as other such products all contain trans-fatty acids.

Trans-fatty acids cause LDL (bad cholesterol) to increase. LDL cholesterol is the type that gets stuck along the walls of veins and arteries. The resulting condition is called arteriosclerosis or hardening of the arteries. This condition can contribute to heart disease and/or strokes. Trans-fatty acids also may decrease HDL cholesterol or the good cholesterol in your blood.

So what is the bottom line? Moderation. According to the experts, reducing all types of fat in the diet is important. Most trans-fatty acids are found in foods like commercial cookies, French fries and donuts fried in solid shortening and other hydrogenated shortening products. A diet low in total fat ­ both saturated and unsaturated ­ can lower your risk of heart disease and many forms of cancer.

Figuring out which foods contain TFAs isn't easy, since they're not listed on nutrient labels. I believe that food manufacturers should disclose on labels whether fats in their products include TFAs, but so far, the FDA hasn't acted on recommendations to make this change in labeling requirements. Be sure to check the labels of any processed foods you buy and avoid those containing hydrogenated or partially hydrogenated oils of any kind.

Additives Used To Decrease Rancidity of Fat or Oil: There are a number of additives which not only impact rancidity but also the flavor and color of the fat or oil. They are: