Types of fat: The good, the bad and the ugly

“Low-fat” and “fat-free” have dominated marketing campaigns in the United States for at least the last two decades, and for those who are trying to lose weight, fat-free seems to be a good idea. However, fats can be very beneficial to your health—if you pick the right types. Priscilla Benavides, registered dietitian and health educator with the Texas A&M Coastal Bend Health Education Center, deciphers what types of fat you should embrace and which you should avoid.

What different types of fat are there?

There are four major dietary fats in the food we eat: saturated, monounsaturated, polyunsaturated and trans and although they all sound bad, that is definitely not the case.

“Your diet should contain plenty of healthy fats,” Benavides said. “It’s really just a matter of picking these healthy fats and adding other nutrients to get a balanced diet.”

Fats have different functions for our body, but their primary role is to provide energy. Fat is energy dense, containing nine calories per gram, whereas protein and carbohydrates only contain about four calories per gram, which makes it very efficient to fuel your body throughout the day. If you consume more calories than you burn off in a day, the excess calories are stored in adipose cells—or fat cells.

These fats all have different impacts on your health, and in particular, different effects on your cholesterol.

Bad fats

The worst type of fat that you’ll find on food labels is trans fats and they have earned their negative stigma. According to the American Heart Association, trans fat can raise your bad cholesterol, lower your good cholesterol and is associated with a higher risk of developing type 2 diabetes.

Although some traces of trans fat occur naturally in meat and dairy, most trans fat can be found in processed or fried foods. “Ideally, you want to have zero trans fat in your diet,” Benavides said. “Trans fat is mostly man-made and can increase your risk for developing heart disease or stroke.”

Be sure to check your nutrition label for trans fats and the ingredient lists for “partially hydrogenated oils,” as they are the primary dietary source for trans fats in processed foods.

In-between fats

While not as “bad” as trans fat, daily consumption of saturated fats should be limited. Found in red meat, whole milk, cheese and tropical oils, such as coconut and palm oil, saturated fats can raise your cholesterol and increase your chances of heart disease and stroke. While it shouldn’t be avoided all-together, this type of fat shouldn’t be the main point of your diet if you’re watching your heart health.

“A lot of people may eat a bit too much of saturated fat, as it’s common in the American diet,” Benavides said. “When we plan out diet plans, we’d like to have about 20 to 35 percent of our calories total calories for adults to come from fat, and less than 10 percent of calories to come from saturated fats.”

Good fats

Unsaturated fats can help lower your bad cholesterols as well as raise your good cholesterol. Your high-density lipoprotein (HDL) is your good cholesterol which can carry your low-density lipoprotein (LDL), or bad cholesterol, from your blood stream to your liver, where it can be properly broken down.

Good fats can be divided into two main categories:  monounsaturated and polyunsaturated fats. Monounsaturated fats are generally liquid at room temperature, but turn slightly solid when chilled. Foods high in monounsaturated fats include olive oil, peanut oil, avocados, nuts and seeds. Polyunsaturated fats are more solid than monounsaturated fats but less so than saturated fats. This makes polyunsaturated fats also liquid at room temperature. Both are beneficial to your overall health, but foods high in polyunsaturated fats—such as corn oil, salmon or mackerel—are further susceptible to going rancid, so be sure to eat them fresh.

“The main difference between the polyunsaturated fat and monounsaturated fat is their chemical compound,” Benavides said. “Overall, both types of unsaturated fats are necessary for a well-balanced diet.”

Creating a diet plan

Be wary about foods that tout low or no fat. Some foods that remove fat have a tendency to increase something else, and that addition may not be healthy either. “If you buy low fat foods that have increased carbohydrates or sugar,” Benavides said, “then you’re really canceling out any health benefits you’re trying to get.”

If you’re trying to improve your health, then the first step that should be taken is creating a plan. Talk to your health care provider or registered dietitian if you have questions about your dietary needs.

“We want to make daily nutrition simple, but it can be very complex,” Benavides said. “The big picture can be extremely beneficial to increasing your health and wellness.”