There’s a lot of discussion and differing opinions about the role of dietary fat in nutrition. It’s a big deal in some popular diets, like the Ketogenic diet, which is high in fat. But in other diets, lowering fat is recommended, especially for heart health or weight management.

So, what does it really mean to increase or decrease fat intake? Is it just about adding or cutting back on oil when we cook? Understanding this can be tricky, so let’s explore the details of dietary fats and how they affect our health below.

What are Dietary Fats

Dietary fats are essential nutrients that play critical roles in our bodies, from providing energy to supporting cell growth and protecting organs. However, not all fats are created equal. And the types and amounts we consume can significantly influence our overall well-being.

Types of Dietary Fat

Saturated Fat

Saturated fat is a type of dietary fat that is usually solid at room temperature. It’s a common topic in nutrition debates, focusing on its health effects, which we’ll explore below.

sliced cheese on clear glass plate

What you need to know

Traditional views link saturated fats to higher LDL (bad) cholesterol levels, a risk factor for heart disease. Not all saturated fats are equal. Some saturated fats, like stearic acid found in chocolate and beef, may not raise LDL cholesterol as much as others. Coconut oil, which contains lauric acid, is another example.

Diets rich in whole foods that contain saturated fats, like dairy and certain oils, can be part of healthy eating patterns, such as the Mediterranean diet.


The American Heart Association (AHA) recommends that only 5-6% of our caloric intake should come from saturated fat. Typically, experts suggest cutting down on foods like:

  • Baked goods
    • Cakes
    • Doughnuts
  • Fried foods
    • Fried chicken
    • Fried seafood
    • French fries
  • Fatty or processed meats
    • Bacon
    • Sausage
    • Chicken with skin
    • Cheeseburger
    • Steak
  • Whole-fat dairy products
    • Butter
    • Ice cream
    • Pudding
  • Solid fats
    • Palm and palm kernel oils (found in packaged foods)

Additionally, for certain heart conditions, it is recommended to strictly reduce saturated fat intake. Here are the extra guidelines:

  • Reduce intake of red meat.
  • Replace whole fat dairy products with low and non fat ones.

Trans Fat

Trans fat is a type of dietary fat created through an industrial process that adds hydrogen to liquid vegetable oils, making them more solid. This process is used to improve the texture, shelf life, and taste of food products.

selective focus photography of burger patty, mayonnaise, and French fries served on platter

Common Sources

Partially Hydrogenated Oils: These are the main dietary source of artificial trans fats.

They’re used in:

  • Deep-Fried Foods: Fast foods like French fries, fried chicken, and doughnuts.
  • Baked Goods: Pastries, cakes, cookies, pie crusts, and biscuits.
  • Margarine: Some margarines and spreads, especially stick margarines.

Processed Foods: Many processed foods contain partially hydrogenated oils to improve texture, flavor, and shelf life. Unsure how to identify trans fats at the grocery store? Check food labels for ingredients like “partially hydrogenated oils”.


This type of fat has been identified to be harmful to our health. They increase LDL (bad) cholesterol, levels while lowering HDL (good) cholesterol levels. This combination raises the risk of heart disease, stroke, and type 2 diabetes. Health organizations like the FDA and WHO recommend minimizing trans fat intake as much as possible.

How can you limit trans fats? Reading food labels carefully and choosing products that do not contain partially hydrogenated oils is a good start. Opting for whole, unprocessed foods and cooking at home with healthier fats like olive oil, avocado oil, and nuts can help reduce trans fat intake and promote overall health.

Unsaturated Fat

Unsaturated fats are a type of dietary fat that are considered healthier compared to saturated and trans fats. They remain liquid at room temperature.

cooked beans

Types of Unsaturated Fat

Monounsaturated fats: Monounsaturated fats have one double bond in their fatty acid chain, which means there is a special connection between two carbon atoms. These carbon atoms are part of the structure that makes up the fat. Sources of these fats include olive oil, avocados, nuts (like almonds and peanuts), and seeds (such as sesame and pumpkin seeds).

Polyunsaturated fats: Polyunsaturated fats have two or more double bonds in their fatty acid chains, which means there are multiple special connections between carbon atoms. These carbon atoms form part of the structure that defines the fat. Polyunsaturated fats include omega-3 and omega-6 fatty acids, essential fats that the body cannot produce on its own. Sources include fatty fish (like salmon, trout, and mackerel), flaxseeds, walnuts, and vegetable oils (such as soybean, corn, and sunflower oils).

Health Benefits

  • Heart Health: Unsaturated fats can improve cholesterol levels by lowering bad cholesterol (LDL) and raising good cholesterol (HDL), which helps reduce the risk of heart disease.
  • Brain Function: Omega-3 fatty acids, a type of polyunsaturated fat, are important for brain health and development, and they help reduce inflammation in the body.
  • Nutrient Absorption: Certain vitamins (like A, D, E, and K) are fat-soluble, meaning they need fat to be absorbed and utilized effectively by the body.

What we need to know

When we encounter a “Low Fat” diet recommendation, this typically indicates a reduction in the overall intake of fats, especially unhealthy fats, to promote better health. A low-fat diet doesn’t mean eliminating all fats but reducing the total amount consumed. Fats should make up about 20-35% of total daily calories while increasing unsaturated fats and significantly lowering saturated and trans fats.

For those on a Keto diet, the majority of fat choices should come from unsaturated fats, not from saturated or trans fats.


Sources such as the UCFS, American Heart Association (AHA), FAO and WHO recommend replacing saturated and trans fats with unsaturated fats as much as possible to promote better health outcomes.

Standard advice from health organizations:

  • Choose healthy oils such as olive oil, canola oil, or avocado oil for cooking and salad dressings instead of butter, lard or mayonnaise.
  • Replace margarine and shortening with these healthier oils when baking or frying.
  • Add flaxseeds, chia seeds, or sunflower seeds to your smoothies, yogurt, oatmeal, or even as snacks.
  • Include fatty fish like salmon, mackerel, trout, and sardines in your meals at least twice a week. These fish are high in omega-3 fatty acids, a type of polyunsaturated fat.
  • Choose lean cuts of meat, such as chicken breast or turkey, and trim visible fat. Opt for low-fat or fat-free dairy products instead of full-fat versions.
  • Limit intake of fast foods, packaged snacks, and baked goods that often contain trans fats and high levels of saturated fats.
  • Cook meals at home using healthier ingredients and methods like grilling, baking, or steaming.
  • Check nutrition labels for trans fats and partially hydrogenated oils. Avoid products containing these ingredients and look for foods labeled “low in saturated fat” or “trans fat-free.”
  • Spread almond butter, peanut butter, or other nut butters on whole-grain bread or use as a dip for fruits and vegetables.
  • Add tofu, tempeh, or edamame to your meals for a plant-based source of protein and healthy fats.

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