Types of Fat: How to Choose Healthier Fats for Your Diet

What Are Fats and Why Do We Need Them?

Dietary fat is a concentrated source of energy that also helps your body absorb vitamins A, D, E, and K. Fat provides essential fatty acids, including omega-3 and omega-6 fats, that your body cannot make in sufficient amounts.

Fat also helps build cell membranes, supports hormone production, and improves the texture and flavor of meals. Foods rarely contain only one kind of fat, so olive oil, cheese, nuts, meat, and packaged foods usually provide a mixture.

The health effect depends on the type of fat and the food pattern around it. Harvard’s Nutrition Source reports that replacing saturated fat with unsaturated fat can improve the balance of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, whereas replacing saturated fat with refined carbohydrates may not provide the same benefit.

What Are the Four Main Types of Fat?

Monounsaturated Fats

Monounsaturated fats contain one carbon double bond and are usually liquid at room temperature. They are common in olive, canola, and peanut oils, as well as avocados, almonds, peanuts, and other nuts.

Using monounsaturated fat instead of butter or fatty meat can reduce saturated fat in a meal. The benefit comes from the substitution, not from adding unlimited oil or increasing total calorie intake.

Polyunsaturated Fats

Polyunsaturated fats contain more than one carbon double bond and include omega-3 and omega-6 fatty acids. Good sources include salmon, sardines, trout, walnuts, flaxseed, sunflower oil, soybean oil, and corn oil.

Omega-3 fats are especially useful because some forms must come from food. The NHS recommends at least 2 portions of fish per week, including 1 portion of oily fish; this guidance was published on a page last reviewed in 2023 and should be re-checked as NHS guidance is updated.

If you do not eat fish, ground flaxseed, walnuts, rapeseed oil, and omega-3-fortified foods can provide plant sources. Plant omega-3 is not identical to the forms found in fish, so ask a clinician or registered dietitian for guidance if you are considering a supplement.

Saturated Fats

Saturated fats have no carbon double bonds and are commonly solid at room temperature. They occur in butter, ghee, fatty cuts of meat, sausage, cheese, cream, ice cream, coconut oil, palm oil, pastries, and many desserts.

Saturated fat can raise LDL cholesterol, although its effect varies by the food and the nutrient replacing it. Harvard’s Nutrition Source identifies replacing saturated fat with polyunsaturated fat as a more reliable heart-health strategy than replacing it with refined grains or added sugars.

Trans Fats

Trans fats have a chemical structure that can result from industrially hydrogenating liquid oils. They were once common in shortening, some margarines, fried foods, and packaged baked goods, although regulations have sharply reduced artificial trans fats in the U.S.

Small amounts of naturally occurring trans fats are present in some meat and dairy foods. Harvard’s Nutrition Source describes trans fats as particularly harmful because they can raise LDL cholesterol, lower HDL cholesterol, and promote inflammation.

Check ingredient lists for “partially hydrogenated oil.” A food can list 0 grams of trans fat per serving while containing a small amount if the amount falls below the labeling threshold, so several servings can add up.

How Do Healthy Fats Compare With Unhealthy Fats?

The phrase “healthy fats versus bad fats” is a useful shortcut, but it oversimplifies nutrition. Unsaturated fats are generally the better choice, while trans fats are the least desirable; saturated fats fit more reasonably into a pattern that emphasizes plant foods, fish, and minimally processed meals.

Use the food source as well as the fat type to judge a choice. A handful of walnuts brings fiber and minerals, while a fried snack may combine fat, refined starch, and sodium.

Dietary fat and disease risk are linked through several factors, including LDL cholesterol, blood pressure, body weight, insulin sensitivity, and overall diet quality. One ingredient cannot predict your personal risk, so discuss persistent high cholesterol or triglycerides with a healthcare professional.

Which Foods Are High in Each Type of Fat?

These foods are common examples, but their fat profiles overlap. Most natural foods contain more than one type of fat.

• Monounsaturated fat: olive oil, avocado, peanuts, almonds, hazelnuts, and canola oil.
• Polyunsaturated fat: salmon, sardines, trout, walnuts, flaxseed, sunflower seeds, soybean oil, and corn oil.
• Saturated fat: butter, cream, cheese, fatty beef, bacon, sausage, coconut oil, palm oil, cakes, and ice cream.
• Trans fat: foods made with partially hydrogenated oil, although these products are now less common in the U.S.; small natural amounts occur in beef and dairy fat.

For lower-cost choices, compare beans, canned fish, peanut butter, seeds, and store-brand olive or canola oil with more expensive specialty products. The practical grocery strategies for eating healthy on a budget can help you plan these swaps without raising your food bill.

How Do Saturated and Trans Fats Affect Cholesterol?

Saturated and trans fats can raise LDL cholesterol, the lipoprotein associated with plaque buildup in arteries. Trans fats may also lower HDL cholesterol, which helps carry excess cholesterol back to the liver.

The NHS states that eating too much saturated fat can raise cholesterol and increase heart disease and stroke risk. Its page, last reviewed April 14, 2023, advises adults to reduce saturated fat and replace some of it with unsaturated fat; re-check the guidance because the review date has passed in 2026.

Try replacing, rather than simply adding, a saturated fat source. For example, use olive oil in place of some butter, choose fish instead of processed meat, or spread mashed avocado on toast instead of a high-saturated-fat spread.

If a blood test shows high LDL cholesterol, high triglycerides, or low HDL cholesterol, food changes may help but may not be enough. Arrange medical advice, especially if you have diabetes, kidney disease, cardiovascular disease, or a strong family history of early heart disease.

How Much Fat Should You Eat?

There is no single fat amount that suits every adult, but the U.S. Dietary Guidelines generally place total fat at 20% to 35% of daily calories for adults. This range should be interpreted alongside age, activity, health status, and total energy needs, and it was checked against federal guidance available in 2026.

For a 2,000-calorie eating pattern, that range equals roughly 44 to 78 grams of fat per day, because each gram supplies 9 calories. Your actual target may differ if you are growing, pregnant, breastfeeding, training heavily, or following a medically prescribed diet.

Harvard’s Nutrition Source reports that the Dietary Guidelines recommend keeping saturated fat below 10% of calories. On a 2,000-calorie pattern, that is fewer than about 22 grams per day, but individual cholesterol goals may call for a lower amount.

Rather than chasing a very low-fat diet, build meals around vegetables, fruit, whole grains, legumes, lean proteins, and measured portions of unsaturated fat. If you are treating a lipid disorder, follow the target set by your clinician.

How Can You Choose Healthier Fats?

Choosing healthier fats means comparing the whole food, checking the label, and using a modest portion. These steps make “how to choose healthy fats” practical at the supermarket:

• Choose oils rich in unsaturated fat, such as olive, canola, or peanut oil, for most everyday cooking.
• Eat fish, particularly oily fish, instead of processed meat when practical.
• Select nuts, seeds, avocado, and olives in portions of about 1 ounce or a small handful.
• Compare saturated fat and serving size on packaged foods, not just the front-of-pack “low fat” claim.
• Scan the ingredient list for partially hydrogenated oil and choose another product if it appears.

The practical guide to reading Nutrition Facts labels explains how to compare serving sizes, total fat, saturated fat, and calories more accurately.

What Easy Swaps Can Make Fats Healthier?

Small substitutions can lower saturated fat without removing satisfying foods from your meals. Try one swap at a time and keep the portion similar.

• Replace some butter in cooking with olive or canola oil.
• Choose plain yogurt with fruit and nuts instead of cream-based desserts.
• Use beans, lentils, fish, or skinless poultry in place of sausage or bacon several times each week.
• Top a sandwich with avocado or hummus instead of mayonnaise or butter.
• Snack on unsalted nuts or seeds instead of pastries, chips, or confectionery.
• Use lower-fat dairy when it helps you reduce saturated fat, but check the ingredient list for added sugars.

Do not treat “fat-free” as automatically healthier. The NHS explains that reduced-fat products can still be high in calories, sugar, or total fat depending on the food, so compare the full label before choosing.

If a dietary change causes unintended weight loss, digestive symptoms, or difficulty meeting your energy needs, speak with a registered dietitian or clinician. People taking cholesterol medication should not stop or change treatment based on food changes alone.