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The Skinny on Dietary Fats: The Best and Worst for Your Health

When you hear the word “fat,” what’s the first thing that comes to mind? For many people, it might bring up thoughts of greasy fast food or poor health.

Sadly, fat has earned itself a bad rap over the years, becoming a stigmatized word in the world of nutrition. But here’s the truth: fat shouldn’t be feared. In fact, it’s an essential nutrient that plays a vital role in helping our bodies absorb certain vitamins, maintain healthy skin and support brain function.

With the help of Jose Velazquez, a registered dietitian with Banner Health, we break down the different types of dietary fats and their importance in maintaining a balanced and healthy diet

Four types of dietary fats

When it comes to fats in our foods, it’s not about being scared of them, but rather understanding which ones are better for us. 

“Different types of fats play a different role in our bodies,” Velazquez said. “It’s important to recognize the fats we eat and how consuming one over the other may have a positive or negative effect on our bodies.” 

The four main types of dietary fats are trans fat, saturated fat, monounsaturated fat and polyunsaturated fat.  

Trans fats: Avoid entirely if possible

Trans fats are artificial fats created through a process called hydrogenation, which turns liquid into solid fat. Also called trans fatty acids or hydrogenated oils, these fats can be found in fried and processed foods like french fries, doughnuts, margarine and packaged snacks. 

“Like saturated fats, trans fats can increase your bad cholesterol levels. But even worse, they can also lower your good cholesterol (HDL),” Velazquez said. “This increases your risk for heart disease, stroke and type 2 diabetes. It’s always best to avoid trans fats completely if possible.”

Saturated fats: Reduce how much you eat

Saturated fats are solid at room temperature and are commonly found in commercially prepared baked goods and animal products like meat, butter, cheese and dairy products. They are also found in some plant-based oils, like coconut and palm oil.

Is saturated fat bad for you? Although some research suggests that saturated fats may not be as harmful as once thought, it’s best to eat foods high in saturated fat in moderation. 

“The reason is that saturated fats can drive up your LDL (harmful cholesterol), which may put you at risk for cardiovascular disease,” Velazquez said. “They also lead to higher fat deposits in your stomach and liver, making it harder to lose weight, higher inflammation and increased insulin resistance—increasing your risk of developing type 2 diabetes.”

The U.S. Department of Health and Human Services recommends limiting saturated fat intake. Try to limit your saturated fat intake to 5% to 10% of total daily calories.

Unsaturated fats: Good in moderation

Polyunsaturated and monounsaturated fats are good fats that mainly come from vegetables, nuts, seeds and fatty fish like salmon, sardines and tuna. These unsaturated fats differ from saturated fats in that they turn to liquid at room temperature, not solid, except for a few solid foods, like avocados.

“Unsaturated fats have shown to reduce LDL cholesterol and increase your HDL cholesterol, helping to maintain healthy cholesterol levels,” Velazquez said.

These types of fats also help:

  • Blood sugar control: Unsaturated fats improve insulin sensitivity and help regulate blood sugar levels.
  • Inflammation: Some unsaturated fats have anti-inflammatory properties
  • Brain function: Omega-3 fatty acids, a type of polyunsaturated fat, are important for brain development and function.
  • Nutrient absorption: Unsaturated fats help the body absorb fat-soluble vitamins like A, D, E and K.
  • Fullness: Foods rich in unsaturated fats tend to be more filling, helping curb your appetite and the overall calories.

Types of monounsaturated fats:

  • Oils (olive oil, canola oil, peanut oil, safflower oil)
  • Avocados
  • Olives
  • Seeds (flaxseeds, chia seeds, pumpkin seeds, sesame seeds)
  • Nuts and nut butter (almonds, cashews, peanuts, pecans)

Types of polyunsaturated fats:

  • Oils (canola oil, corn oil, flaxseed oil, soybean oil, sunflower oil)
  • Fatty fish (albacore tuna, anchovies, mackerel, salmon, sardines)
  • Walnuts
  • Seeds (flaxseed, sunflower seeds)
  • Tofu, soybeans

You’ll find many of these healthy types of fats in the Mediterranean diet.

Finding balance

The key to a healthy diet is finding balance, which includes eating the right fats in moderation. Velazquez shared some tips to help you make healthier choices:

  1. Cook at home: Prepare meals using fresh, whole ingredients whenever possible. This allows you to control the types and amounts of fats you use in cooking. Pair with lean protein, whole grains and non-starchy vegetables. Bake, grill or steam instead of frying. Use unsaturated fat oils (like olive or sunflower) and salt-free seasonings when cooking. 
  2. Read food labels carefully: Pay attention to nutrition labels on packaged foods to identify the types and amounts of fats they contain. Always look at the serving sizes, the total carbohydrates, the total fat and the type of fats it contains. Also, some products may have “hidden” trans fats. Don’t assume zero grams means there are no trans fats. If the product has up to 0.5 grams, the label may say 0 grams. Look for the words hydrogenated or partially hydrogenated in relation to the oils in the product.
  3. Be wary of marketing lingo: Products labeled low calorie, sugar-free, or fat-free often use other ingredients to maintain taste and texture. These substitutions may include artificial sweeteners, preservatives or refined carbohydrates, which means the products aren’t entirely healthy.
  4. Watch portion sizes: While fats are essential for a balanced diet, it’s important not to overdo it. Use measuring tools or familiarize yourself with appropriate portion sizes to avoid overeating. Here are some tips for not overdoing it at restaurants and social events.
  5. Be mindful of hidden fats: Be aware of hidden fats in foods such as sauces, salad dressings and condiments. These can add up quickly. Use sparingly or make your own alternatives.


Dietary fats often get a bad rap, but they’re essential to a balanced diet. By understanding the different types of fats and making smart choices, you can enjoy delicious foods while supporting your overall health and well-being.

If you have specific dietary concerns or health conditions, talk to your health care provider, a registered dietitian or Banner Health specialist for personalized guidance on incorporating fats into your diet.

For more nutrition tips, check out:

Cholesterol Diabetes Heart Health Wellness Weight Loss Nutrition