What are dietary fats?

Dietary fat may have a bad reputation, but fat is vital for your health. The body actually needs fat for energy and for many critical processes such as the absorption of certain vitamins and minerals.

For several decades, American grocery stores have been stocked with an assortment of fat-free and low-fat food products. Because fat is high in calories, eliminating it seemed like a good way to manage weight and improve health.

Unfortunately, added sugars and refined carbohydrates are often used to replace fat in processed foods. That adds up to a lot of extra calories with little to no nutritional value.

There’s one bad fat that you should avoid, though: trans fats. They have no nutritional value and are harmful to your health.

They’re often found in:

  • fried foods
  • processed snacks
  • baked goods

In June 2015, the U.S. Food and Drug Administration (FDA) announced its position that partially hydrogenated oils, the main source of artificial trans fat in processed foods, aren’t “generally recognized as safe” to eat. Food manufacturers have 3 years to phase them out.

This process has already begun. The World Health Organization (WHO) is working to eliminate trans fats from the global food supply by 2023.

Two other types of dietary fat are saturated and unsaturated fat. Rather than trying to cut fat, learning more about these two types of fat and how they affect your body is more helpful.

Fats that are tightly packed with no double bonds between the fatty acids are called saturated fats. There are some exceptions, but most are solid at room temperature.

Sources of saturated fat include:

  • fatty pieces of meat such as beef and lamb
  • some pork and chicken products
  • dairy products including cream, whole milk, butter, shortening, and cheese
  • coconut and palm oils

The debate over whether consumption of saturated fat is bad for heart health has been ongoing for decades. Research studies offer conflicting findings regarding the impact of saturated fat on heart health, making this topic particularly confusing for consumers.

While it’s clear that saturated fats raise blood lipids, including low-density lipoprotein (LDL) cholesterol levels and certain other heart disease risk factors, such as inflammation, it’s unclear whether saturated fats increase the risk for heart disease.

For example, a 2014 review of 32 studies that included 27 randomized control trials involving over 650,000 people found no association between saturated fat intake and heart disease risk.

The review concluded that, “Current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats.”

However, other studies have shown that saturated fat intake may increase the risk for heart disease.

While research on this subject is ongoing, it’s important to keep in mind that saturated fat is just one piece of your dietary intake. What matters most for maintaining your health and reducing your disease risk is the overall quality of your dietary intake and lifestyle.

A diet high in saturated fat may raise your low-density lipoprotein (LDL) cholesterol levels, which will raise your risk for heart disease and type 2 diabetes.

An early study showed that grass-fed beef may elevate cholesterol less than grain-fed beef. Grass-fed lean beef usually contains less fat.

The typical American diet is too high in saturated fats.

Unsaturated fats are loosely packed. They tend to be liquid at room temperature.

There are two main types of unsaturated fat:

Monounsaturated fats

Research shows that consumption of plant-based monounsaturated fats may help lower your risk for cardiovascular disease and overall mortality.

Foods that are highest in monounsaturated fats include:

  • olive oil
  • peanut oil
  • avocados
  • most nuts
  • most seeds

Polyunsaturated fats

Your body needs polyunsaturated fats to function. Polyunsaturated fats help with muscle movement and blood clotting. Since your body doesn’t make this type of fat, you have to get it through your diet.

Polyunsaturated fats can be further divided into two types: omega-3 and omega-6 fatty acids.

Omega-3 fatty acids are beneficial for heart health.

The best sources of omega-3 fatty acids are:

  • fatty fish, such as sardines, tuna, salmon, trout, mackerel, and herring
  • ground flax and flaxseed oil
  • soybeans
  • oysters
  • walnuts
  • sunflower seeds
  • chia seeds
  • hemp seeds

There’s debate about the inflammatory role of omega-6 fatty acids. Most Americans consume more than enough of them. Consuming too many foods rich in omega-6 fats may increase inflammation in your body and raise your risk for certain health conditions, including obesity.

Omega-6 fatty acids can be found in:

  • canola oil
  • safflower oil
  • soybean oil
  • sunflower oil
  • walnut oil
  • corn oil

According to Harvard Medical School, recent research reveals that there’s not enough evidence that saturated fat raises your risk for cardiovascular disease.

However, according to a 2017 study, evidence suggests that choosing polyunsaturated fats in place of saturated fat may reduce the risk. That’s not the case if you replace saturated fat with sugar and processed carbohydrates.

Some oils may have more health benefits than others. Canola oil, although considered an unsaturated fat, is highly refined. According to a 2018 study, research has shown that it may have negative effects on health. Eating oils in moderation and varying your intake of types of oils is recommended.

A 2016 study has found that repeatedly heating vegetable oils can decrease their antioxidant activity and increase free radical production, which may lead to poor health effects. Avoid overheating or burning of vegetable oils to keep their nutrient content.

People need fats, so you don’t have to do without them. However, regulatory authorities recommend that you eat saturated fat in moderation.

The American Heart Association recommends limiting your intake of saturated fat to less than 6 percent of your daily calories. That translates to about 120 calories, or about 13 grams per day on a 2,000-calorie daily diet.

According to the Cleveland Clinic, total fat intake should be between 20 and 35 percent, which is equal to 44 to 77 grams of total fat daily on a 2,000-calorie diet.

However, research shows that certain higher fat diets, such as the Mediterranean diet, and low-carbohydrate diets, are beneficial for overall health. Ultimately, your energy needs, genetics, and lifestyle are the best indicators of your macronutrient needs.

Choosing to incorporate nutritious sources of fat in your diet can benefit your health in many ways, including:

  • increasing satiety and reducing hunger
  • helping you maintain a healthy weight
  • improving blood lipid levels

However, all fats are not created equal.

The following table can help you choose the healthiest fat sources.

Unhealthy sources of fat

Healthy sources of fat

margarine

olive oil, avocado oil, and coconut oil

ice cream, icing, and other high-fat, sugary foods

unsweetened whole or low-fat yogurt

high-calorie fatty beverages such as whole chocolate milk

fried foods

vegetable shortening

avocados

unsweetened coconut

olives

processed meats such as bacon and lunchmeats

nuts, seeds, and nut butters

refined vegetable oils, including canola oil

packaged high-fat foods such as chips and cookies

high-fat fish such as salmon and sardines

whole eggs

chia and hemp seeds

Other high-fat foods such as cheese and butter can fit into a healthy lifestyle as well. Just use moderation with these and other high-fat foods as they’re rich in calories and can lead to weight gain if overconsumed.

When preparing meals, keep in mind that certain fats are more appropriate for high-heat cooking methods, while others should only be added to dishes after cooking because they’re more heat sensitive.

For example, extra virgin olive oil or avocado oil work well for sautéing or pan-frying, while delicate oils such as walnut and flax oils should only be used to flavor dishes after cooking.

Here are some healthy eating tips:

  • Sauté with olive oil or avocado oil.
  • Bake with olive, sunflower, coconut, or avocado oil.
  • Bake, broil, or grill seafood and poultry instead of frying.

When grocery shopping, read nutrition labels carefully. Be cautious when buying reduced-fat products as the fats are often replaced with sugars and other additives that aren’t good for your overall health.

The easiest way to ensure that you’re choosing healthy items when shopping is to fill your cart with mostly whole, unprocessed, nutrient-dense foods like vegetables, fruits, filling protein sources, and healthy fats.

Healthy eating starts with a diet rich in whole foods, including sources of healthy fats like avocados, nuts, seeds, eggs, and olive oil.

Just as overconsuming any macronutrient can cause weight gain, eating too many fat-rich foods can cause you to gain weight if the calories aren’t accounted for elsewhere in your diet.

Having overweight or obesity can raise your risk for heart disease and other chronic health conditions like diabetes.

However, fats are an essential part of the diet. Try to choose the right types of fats and to enjoy them in moderation as part of a healthful eating plan.