Good Fats & Bad Fats

The terms "good fat" and "bad fat" you may have heard refer to fat's potential to cause disease. All fats have the same amount of calories, but they vary in their chemical compositions and effects on health. Fats are made of chains of carbon and hydrogen atoms. The saturation refers to whether all the available spaces on the carbon chain are bonded to hydrogen atoms, or if there are any hydrogen atoms missing. The three forms of fat found in nature are:

Saturated Fats
These fats have all of their carbon atoms filled (saturated) with hydrogen. Saturated fat is primarily found in high-fat cuts of meat, poultry with the skin, whole and 2 percent dairy products, butter, cheese, and tropical oils: coconut, palm, and palm kernel. Our body needs a small amount (about 20 grams) of saturated fat each day, but the typical American diet usually exceeds that amount. Too much saturated fat may cause a person's bad cholesterol (LDL) to rise and may also increase the risk of developing certain types of cancer. You can look for the amount of saturated fats in a serving of food on the nutrition label, under the heading "Saturated Fat" below the larger heading of "Total Fat."

Monounsaturated Fats
These fats have one space missing a hydrogen atom, instead containing a double bond between two adjacent carbon atoms. Monounsaturated fat is found in olive oil, canola oil, peanut oil, and in most nuts and nut butters. This type of fat does not cause cholesterol to increase. When a person substitutes monounsaturated fat for saturated fat, it helps to lower the bad cholesterol and protects the good cholesterol (HDL) from going down. The amount of monosaturated fats (and polyunsaturated fats, see below) is not listed separately on the food label, but it can be calculated by subtracting the saturated and trans fats (see below) from the total fat.

Polyunsaturated Fats
These fats have more than one hydrogen atom missing in the carbon chain and therefore contain more than one double bond. The two major categories of polyunsaturated fats are Omega-3 and Omega-6 fatty acids. Omega-3 means there is a double bond in the third space from the end of the carbon chain. These fats are extremely healthful in that they protect against sudden death from heart attack. They can also help people lower their triglycerides. Omega-3s are used by the body to produce hormone-like substances with anti-inflammatory effects. The best sources of Omega-3s are fatty fish, such as salmon, sardines, mackerel, herring, and rainbow trout, among others. Canola oil, walnuts, and flaxseed also contain some Omega-3s.

Omega-6 fats have a double bond in the sixth space from the end of the carbon chain. These fats are found in oils such as corn, soybean, cottonseed, sunflower, and safflower. Omega-6 fatty acids are used in hormone-like substances that promote inflammation. Replacing saturated fats with Omega-6 fats may reduce levels of total, bad, and good cholesterol. Many health experts suggest that the ratio of Omega-6 to Omega-3 fatty acids should be 4:1 for optimal health. (Most Americans get anywhere from 14:1 to 20:1 — a lot more than needed!) These fats are not listed separately on the food label.

The other type of fat that is found in food, but isn't natural, is hydrogenated or partially hydrogenated fat - commonly called trans fat.

Hydrogenated Fats (also known as Trans Fats)
These are manufactured by adding hydrogen to a polyunsaturated fat, making it solid at room temperature.