Why You Need Good Fats and Where to Find Them

Canola oil is a healthy fat.
Creativ Studio Heinemann / Getty Images

Fat provides a rich texture and flavor. The foods that contain the largest amounts include meat, dairy, eggs, nuts and seeds. Typical examples of cooking fats include olive oil, lard, canola oil, butter, margarine, and shortening.

You need to eat fats -- good fats are necessary for a healthy body. But you also need to avoid some fats. Specifically , the bad fats that raise your cholesterol and increase inflammation.

 

First, a Little Chemistry

Fats are made up of individual molecules called fatty acids, which are chains of carbon atoms along with some oxygen and hydrogen atoms. The carbon atoms in the fatty acid molecules are linked by single or double bonds.

Fatty acids vary in length. Short-chain fatty acids have two to four carbon atoms; medium chain fatty acids have six to 12 carbons atoms, long fatty acids have 14 to 18 carbon atoms. A few fatty acids have more than 20 carbon atoms chains.

Fatty acids are either saturated or unsaturated. Saturated fatty acids have no double bonds between any of the carbon atoms in the chain. Saturated fatty acids are solid at room temperature (think of the fat on red meat). Unsaturated fatty acids have one or more double bonds in the carbon chain. Monounsaturated fatty acids have one double bond, and polyunsaturated fatty acids have two or more.

Unsaturated fatty acids are sometimes named by the position of the double bonds in the carbon chain.

The names omega-3, -6 or -9 refer to the locations of the first double bond in the three different fatty acid molecules.

The monounsaturated and polyunsaturated fatty acids are liquid at room temperature (think of vegetable oil).

Unsaturated fatty acids can have two different configurations of the hydrogen atoms that are located on either side of the double bonds.

These are referred to as "cis" or "trans" configurations. Cis configurations have those hydrogen atoms both on the same side of the molecule. Cis configurations cause the molecule to look like it is bent. Trans configurations have those hydrogen atoms on opposite sides of the double bond, which gives the molecule a linear appearance, like saturated fats.

Fats (and cholesterol -- a type of fatty substance that is mostly made by your liver, but some comes from your diet) have a number of important functions, which include:

  • Lubrication of body surfaces
  • Components of cell membrane structures
  • Formation of steroid hormones
  • Energy storage
  • Insulation from cold
  • Carrying fat-soluble vitamins A, D, E, K

Good Fats and Bad Fats

Some fats are better for your health than others. The polyunsaturated and monounsaturated fatty acids are usually good, and most saturated fats are bad. The largest amounts of polyunsaturated fats are found in plants, such as in seeds, nuts and vegetable oils. Fish and seafood are also rich in polyunsaturated fats.

Olive oil, canola oil, avocado, and nuts also contain monounsaturated fatty acids, which are good for your heart and blood vessels.

The bad fats included some types of saturated fats and trans fats. People who eat large amounts of saturated fats from red meats tend to have higher cholesterol levels than people who eat mostly plant-based foods. Plus they're at risk for inflammation and cardiovascular disease. Still, it isn't clear if all types of saturated fatty acids are bad.

It is clear, however, that most trans fats are bad. Most trans fats are formed when hydrogen is forced into liquid vegetable oils to make them semi-solid.

Some types of stick margarine contain large amounts of trans fats, and some highly processed foods have trans-fats. Some naturally occurring trans-fats are in dairy products; however, they don't seem to be as detrimental as the trans-fats that are created artificially.

Eating a healthy diet means you need to eat fewer trans fats and saturated fats and more of the polyunsaturated and monounsaturated fats. This week you're going to work on both.

The United States Department of Agriculture suggests that about 30 percent of your calories come from fats, but many people eat much more fat than that. You can start by choosing low-fat and non-fat foods at the grocery store and by choosing recipes that are low in fat. Generally, you should:

  • Cut back on creamy sauces and oily dressings.
  • Avoid fried foods.
  • Stay away from highly processed foods (or at least read the labels to choose the products with the least amount of total fat).
  • Don't eat rich desserts that are high in sugar and fat.
  • Use non-stick cookware and non-stick cooking spray instead of butter and oils.
  • Choose baked chips and snacks that are lower in fat than regular chips.

Red meat is high in saturated fats, especially the fattier cuts of meat and ground beef. Eggs, dairy products like cream, whole milk and cheese, tropical oils and coconut oil are also high in saturated fats.

These aren't "bad foods," but you need to watch how much you're eating of these products. Processed lunch meats, hot dogs, sausages, and bacon are very high in saturated fats (and they contain chemicals that are bad for you), and should be avoided.

Here are some steps you can take to reduce your consumption of saturated fats:

  • Choose non-fat or low-fat milk, yogurt, and cheese every day.
  • Trim fat from red meats before cooking or choose lean cuts of meat.
  • Eat red meat just two or three times each week.
  • Remember that one serving of red meat should be about the size of a deck of cards.
  • Choose poultry (remove the skin), and fish more often. Bake, grill or broil chicken, and fish, but don't fry them.
  • Avoid foods that are battered and fried. They're high in calories and bad fats.
  • Eat more legumes like dry beans, soy and lentils. They contain lots of protein and fiber, and no saturated fat.

Trans fats can be avoided by choosing margarine that is not made with trans fats (read the Nutrition Facts label -- it should show zero servings of trans-fat and the ingredients should not list "partially hydrogenated oils." You should also avoid the highly processed foods like potato chips, tortilla chips and cheese snacks that are fried in trans fats, or other snack items baked with trans fats. Many of those snack items are high in sugar, so you gave them up in week two.

Olive oil is a well-known source of monounsaturated fatty acid and is a central component of the Mediterranean diet, which is associated with good health. Extra virgin olive oil is a good choice because it also contains phytochemicals called polyphenols that are beneficial for your body.

Canola oil, nuts, and avocados also contain some monounsaturated fats. Canola has a light flavor, so it works well for cooking and baking. Nuts are also rich in protein and help to keep you feeling full between meals. Here are some ideas for increasing the monounsaturated fats in your diet:

  • Top your salad with olive oil and balsamic vinegar.
  • Drizzle olive oil on your favorite vegetables.
  • Add slices of avocado to salads and sandwiches.
  • Enjoy a handful of nuts as a mid-meal snack.
  • Add chopped nuts to a bowl of oatmeal, to your salad, or on top of a vegetable side dish.

There are two types of polyunsaturated fats called omega-3 fatty acids and omega-6 fatty acids. Omega-3 fats are found in fish, chia seeds, flax, soy, walnuts and canola oil. Omega-6 fats are found in varying amounts in nuts, seeds, grains and vegetable oils. Most red meat is low in polyunsaturated fats, but animals raised on grass instead of corn-based feeds have meat that has more polyunsaturated fats and lower in fat in general.

You're probably already eating plenty of the omega-6 fats unless you're eating a low-fat diet. The omega-6 fatty acids are common in a typical Western diet (linoleic acid in the vegetable oil and conjugated linoleic acid in milk and meat), but the omega-3 fatty acids are often deficient. Many experts believe that eating a diet with too many omega-6 fats and too few omega-3 fats increase your risk for inflammation and chronic disease. You can correct that imbalance that by choosing more omega-3 fatty acids:

  • Choose canola oil instead of corn oil or safflower oil for cooking and baking.
  • Sprinkle milled flax seeds on your salads.
  • Take a tablespoon of flax seed oil as a daily supplement.
  • Eat fish two or three times per week. Salmon, tuna, and trout are all rich in omega-3 fatty acids.
  • Soy is rich in protein and omega-3 fatty acids. Try tofu in a stir-fry.
  • Enjoy walnuts or pumpkin seeds as snacks. Both contain substantial amounts of omega-3 fatty acids.

Sources:

"Dietary Guidelines for Americans," United States Department of Health and Human Services. January, 2010. Accessed April 13, 2016. http://health.gov/dietaryguidelines/2010/.

Gropper SS, Smith JL, Groff JL. "Advanced Nutrition and Human Metabolism." Fourth Edition. Belmont, CA. Wadsworth Pub Co. 2005. Accessed April 13, 2016.

Continue Reading