Sometimes when we hear the word "fat" we automatically have a negative connotation with that word. Actually, we need some fats in our diets. But it is important to choose the right kinds of fats.
Fats are necessarily for protecting our internal organs, for insulation, for hormones, found in our nerve and brain tissues, and for storage and transport of some vitamins. They are also a concentrated source of energy and help satisfy hunger and fullness. Fats can also raise our blood cholesterol.
Saturated fats come mainly from animal foods, such as higher fat cuts of meat, butter, whole dairy products (milk, cheese, yogurt) and from palm, palm kernel, and coconut oils. Saturated fats are typically solid at room temperature (except those three oils previously listed) and raise both total cholesterol and bad (LDL) cholesterol. It is recommended to consume no more than 7 to 10% of total calories from saturated fat (look for foods that have 5% or less %DV for saturated fat).
Trans fats (or hydrogenated fats) are processed to be more saturated and found in many packaged foods, bakery foods, stick margarine, and fried restaurant foods. You will find them in some donuts, cookies, crackers, cakes, margarine, muffins, and fried foods. Look for the word "partially hydrogenated" in the ingredient list. It is recommended to get as little trans fat as possible, as close to none as you can. Trans fats also raise total cholesterol and bad (LDL) cholesterol, and may also lower good (HDL) cholesterol.
Monounsaturated fats are liquid are room temperature and include nuts, vegetables oils (canola, olive, sunflower, safflower oils), and avocados. They lower total cholesterol, lower bad (LDL) cholesterol, and may raise good (HDL) cholesterol.
Polyunsaturated fats are also liquid at room temperature and include oils (corn, safflower, soybean, and sunflower oils) and the fatty acids from seafood. They lower total cholesterol, lower bad (LDL) cholesterol, and may lower good (HDL) cholesterol.
Omega-3 fatty acids are a special type of polyunsaturated fats but are unique. They are found in seafood (mainly oily fish like tuna, mackerel, and salmon) and to a lesser extent in walnuts, flaxseed, and some oils (soybean, canola). Seafood is the best source of omega-3 fatty acids. Omega-3s will lower triglycerides and total cholesterol.
All fats and oils are made of up a combination of these different types.
You can compare the different makeup of fats and oils on this comparison chart. If the graphic is too small, click on the link.
Other resources:
Which Fats and Oils are Healthy? from MU Extension (Janet Hackert)
Do You Know Your Cholesterol Numbers? from MU Extension (Tammy Roberts)