Weight Loss: Are All Dietary Fats Created Equal?

Nutrition is a tough word to define. We all think we know how to eat nutritiously, but in this day and age it can be extremely difficult to truly understand what’s in our food and what’s considered healthy. Are all grains/proteins healthy? Are all types of fats/carbohydrates bad?

The goal is to fuel your body with nutrients including: proteins, carbohydrates, fats, vitamins, minerals, and water. To accomplish this, the key is to:

•    Eat a variety of foods, including vegetables, fruits, and whole-grain products.

•    Eat lean meats, poultry, fish, beans, and low-fat dairy products.

•    Drink lots of water.

•    Limit salt, sugar, alcohol, saturated fat, and trans fat in your diet.

It’s estimated that 20-35% of our caloric needs should come from fats, let’s begin the discussion there. . .but which ones are healthier than others?

Trans Fat:

Goal: Limit or eliminate

Trans fats are liquid oils bombarded with hydrogen so they stay solid at room temperature. Think of belly fat! They’re found in many processed and fried foods.

Trans fats increase total cholesterol and LDL, or bad cholesterol, and lower HDL, the good cholesterol, the exact opposite of our goal.

Food manufacturers can say a product is trans fat free if it contains less than half a gram per serving. These can add up. Check a product’s ingredient list. If you see the words hydrogenated, partially hydrogenated, or shortening, it contains trans fat; you’re better off not buying it.

Unsaturated Fat:

Goal: Increase

The two main types of unsaturated fats are monounsaturated and polyunsaturated fats; their chemical structure is slightly different, as are their health benefits.

Generally, unsaturated fats are mostly good- although trans fat is technically an unsaturated fat. However, healthy unsaturated fats are liquid at room temperature, while trans and saturated fats are solid.

To increase your unsaturated fat, replace solids, like butter, with olive and vegetable oils, and swap red meat for seafood or unsalted nuts. Seafood and nuts also contain saturated fat, but usually less than red meat.

Saturated Fat:

Goal: Decrease

Saturated fat increases total cholesterol and LDL, and may boost your Type 2 Diabetes risk. Meat, seafood, and dairy products are sources of saturated fat. Some plant foods, like palm and coconut oils, also contain it saturated fat. Saturated fats from plant or animals are just as concerning.

Choose low-fat or fat-free dairy products to get their key nutrients, while cutting saturated fat.

The Dietary Guidelines recommend no more than 10% of total calories come from saturated fat. So, if you eat 2,000 calories a day, for example, keep your saturated fat intake below 22 grams.

Monounsaturated Fats:

Goal: Increase

Monounsaturated fats raise HDL (good cholesterol) and lower LDL (bad cholesterol). Canola oil, olive oil, peanut oil, nuts, seeds, and avocados are good sources of monounsaturated fats.

Trade sour cream dip for hummus (which is rich in olive oil) or guacamole; use veggies or whole-wheat chips to dip. Try peanut oil in a stir-fry to jazz up your diet while helping your heart, says Sari Greaves, who is an American Dietetic Association spokesperson and coauthor of The Cardiac Recovery Cookbook.

Unsalted nuts contain monounsaturated fat, but they’re high in calories. Sprinkle them on salads or yogurt, rather than eating a 170-calorie handful.

Polyunsaturated Fats:

Goal: Increase

You can find polyunsaturated fats in nuts, seeds, fatty fish, and vegetable oils such as corn and safflower oil. This category encompasses omega-3 and omega-6 fatty acids, which are known as essential fatty acids because our bodies don’t make them- we have to get them from food. These fats can help lower your total cholesterol.

The following graph from the 2015-2020 Dietary Guidelines for Americans, shows the composition of dietary fats as a combination of Saturated, Monounsaturated, and Polyunsaturated Fatty Acids. “Dietary fats are found in both plant and animal foods. They supply calories and help with the absorption of the fat-soluble vitamins A, D, E, and K. All dietary fats are composed of a mix of polyunsaturated, monounsaturated, and saturated fatty acids, in varied proportions,” the guide explains.

DATA SOURCES: U.S. Department of Agriculture, Agricultural Research Service, Nutrient Data Laboratory. USDA National Nutrient Database for Standard Reference.
Release 27, 2015. Available at: http://ndb.nal.usda.gov/.

Cholesterol:

Goal: Decrease

Scientific understanding of the dangers of dietary cholesterol has shifted. “It used to be thought that eating dietary cholesterol, like in shrimp or eggs, would raise cholesterol,” Suzanne Rostler, a registered dietitian and nutritional professional, explains. “It does to some extent, but it’s more important to focus on not eating saturated and trans fats.”

For people with normal cholesterol levels, Rostler says, the current recommendation is no more than 300 milligrams of cholesterol daily, while people at high risk of heart disease should consume less than 200 milligrams daily. For perspective, one egg contains about 200 milligrams of cholesterol.

Omega-3 Fatty Acids:

Goal: Superstars

Omega-3 fatty acids are wonderful. They fight inflammation, help control blood clotting, and lower blood pressure and triglycerides.

Fatty fish like albacore tuna, salmon, mackerel, and sardines are good sources, even the canned ones.

Vegetable sources include soy, walnuts, and some vegetable oils. There are no specifics on how much you should consume, but the American Heart Association suggests eating at least two, 3.5-ounce servings of fish each week.

Omega-6 Fatty Acids:

Goal: Unclear

Most of us have no trouble getting enough omega-6s, which are found in vegetable oils and many snack foods.

The ratio of omega-6s to omega-3s in the typical Western diet is around 10 to 1. Some research suggests that between a 2-to-1 and a 4-to-1 ratio reduces the risk of death from heart disease.

There has been some controversy over whether omega-6s can actually be harmful to the heart, but Greaves and Rostler agree that there is a benefit if you’re eating them instead of saturated or trans fats, and you make a point of upping your omega-3 intake.

About half of all adult Americans have one or more diet preventable chronic diseases such as Type 2 DM, CVD and weight issues. Evidence shows that healthy eating patterns and exercise can significantly impact these diseases. In the coming posts, we’ll look into other nutritional factors, such as fiber, proteins, carbohydrates, vitamins. . .and how to read nutritional labels.

-Dr. Courtney

For more information, the Dietary Guidelines referenced throughout this post can also be read here.