Know your fats and oils

May 4, 2021

Expert guest blog: Christina Boydston, RDN, LDN, Clinical Dietitian

Why do I need fat in my diet?

Fat is an essential nutrients in our diet, along with protein and carbohydrates. Critical to a healthy and balanced diet, fats serve as fuel and are carriers for Vitamins A, E, D, and K.

But not all fats are the same. Certain fat sources are better choices than others, based on their intended use and nutrition profiles.

Saturated, Unsaturated, Trans-fats – what’s the difference?

Saturated fats are normally “solid” at room temperature – think butter, lard, palm oil, beef fat (tallow), or coconut oil (this one is tricky as it is called an “oil”). Saturated fats need to be limited in a normal, healthful diet as they can raise cholesterol levels, especially the “bad” LDLs. These, along with “trans” fats, may increase the risk of heart disease. Trans-fats should be avoided and to do this, look for the word “hydrogenated” on an ingredient list. If you see this word, put that item back on the shelf—your heart will thank you!

Unsaturated fats are normally liquid at room temperature – think olive, sunflower, safflower, canola, corn, soybean, peanut, avocado, and the generic “vegetable oil” blends. Blended margarines such as Smart Balance, while “solid” at colder temperatures, will soften and partially liquefy at room temperature. Some of these oils contain the famous “omega” oils that can be more heart-healthy when used in moderation. Bear in mind, however, that while some may be considered more “heart-healthy,” fats are very calorie dense and a little goes a long way.

Shopping for and using cooking oil

So what should you look for when you are in the cooking oil isle of the grocery store?

Canola oil is a good choice for higher temperature cooking and baking. It has a small amount of omega-3 fats and is mostly unsaturated fat.

Olive oils are best for sautés, salad dressings, and low temperature baking. Containing a smaller amount of omega-3 than canola, this oil lends its delicate flavor well in salad dressings and sprinkled lightly over plain pasta.

Avocado oil is a great choice for sautés, frying, and higher temperature baking. It also lends a delicate flavor to dishes.

Corn, sunflower, and peanut oils are good for frying. Consume fried food rarely in a balanced diet as they are very calorie and fat dense.

If you’re looking to boost the heart-healthy omega-3s, flax oil contains the highest amount compared to most oils. As a rule, you want to look for a flax oil that has been processed and stored at low temperatures and kept cold. This is a great choice for salads, salad dressings, and smoothies. It is best not to heat or cook with this oil, as heating above room temperature will change its fat profile.

Always store oils away from heat in your kitchen and smell them before you use them. If they have no odor or only a slight odor, they are good. If they have a strong, pungent or “sour” smell, they are bad (rancid) and should be thrown away and/or replaced.

Along with a balanced diet and daily activity, fats are necessary, in moderation, for a healthful (and flavorful) diet.