Healthy fats are unsaturated fats found in foods like olive oil, avocados, nuts, seeds, and fatty fish. The World Health Organization recommends that fat make up no more than 30% of your daily calories, with most of it coming from these unsaturated sources and less than 10% from saturated fat. Choosing the right types of fat can lower harmful cholesterol, reduce inflammation, and meaningfully cut your risk of heart disease.
Monounsaturated Fats
Monounsaturated fats are one of two main categories of unsaturated fat. They have a flexible chemical structure that keeps them liquid at room temperature (think of a bottle of olive oil on your counter). Their primary benefit is improving your cholesterol balance: they help lower LDL (“bad”) cholesterol while supporting HDL (“good”) cholesterol. They do this partly by increasing the number of receptors in your liver that pull LDL out of your bloodstream.
The richest everyday sources include:
- Olive oil (especially extra-virgin)
- Avocados and avocado oil
- Nuts like almonds, cashews, hazelnuts, and peanuts
- Olives
These foods are central to the Mediterranean diet, which has been extensively studied. Meta-analyses published in the American Heart Association’s journals found that strong adherence to this eating pattern reduced cardiovascular disease risk by roughly 20% to 36% across multiple trials. Stroke risk dropped by 16% to 32%. The common thread in those studies is a diet built around olive oil, nuts, fish, and vegetables rather than butter, red meat, and processed food.
Polyunsaturated Fats: Omega-3s and Omega-6s
Polyunsaturated fats include two families you’ve likely heard of: omega-3 and omega-6 fatty acids. Both are essential, meaning your body cannot make them on its own. You have to get them from food.
Omega-3 Fatty Acids
Omega-3s come in three main forms. ALA is found in plant foods like flaxseed, chia seeds, hemp seeds, and walnuts. EPA and DHA come from marine sources, primarily fatty fish such as salmon, sardines, anchovies, and tuna. Your body can convert small amounts of ALA into EPA and DHA, but the conversion rate is low, so eating fish (or taking a marine-based supplement) is the most reliable way to get EPA and DHA directly.
Omega-3s are best known for reducing inflammation. In a large analysis using UK Biobank data, a 1% increase in blood omega-3 levels was associated with a measurable drop in C-reactive protein, one of the body’s key inflammation signals. This anti-inflammatory effect is one reason omega-3s are linked to lower cardiovascular risk. It also appears to benefit lung function and may help people with chronic inflammatory conditions.
Omega-6 Fatty Acids
Omega-6s are found in vegetable oils like safflower, sunflower, corn, and soybean oil, as well as in soybeans, edamame, and tofu. They also lower LDL cholesterol when they replace saturated fat in your diet. The concern you sometimes hear about omega-6s “causing inflammation” is largely outdated. In the context of a balanced diet that also includes omega-3s, omega-6 fats from whole foods and cooking oils are not harmful.
Best Nuts and Seeds by the Numbers
Nuts and seeds pack an impressive amount of unsaturated fat, protein, and fiber into a small serving. Here’s how a few popular options compare per ounce, based on data from Harvard Health Publishing:
- Walnuts: 16 grams of unsaturated fat, 2 grams of saturated fat, 3 to 7 grams of protein, and 1 to 3 grams of fiber. Walnuts are one of the few nuts that are particularly high in ALA omega-3s.
- Almonds: 12.5 grams of unsaturated fat, 1 gram of saturated fat, 3 to 7 grams of protein, and 1 to 3 grams of fiber. They’re slightly lower in total fat than walnuts, making them a good option if you want the benefits with fewer calories.
- Chia seeds: 4 grams of fiber per tablespoon. They’re rich in ALA omega-3s and absorb liquid, making them easy to add to smoothies or oatmeal.
- Hemp hearts: 1 gram of fiber per tablespoon, with a milder flavor that works well sprinkled on salads or yogurt. They provide a balanced ratio of omega-3 to omega-6.
All nuts and seeds fall in the 160 to 200 calorie range per ounce. A small handful daily is enough to get their benefits without overshooting on calories.
Choosing the Right Cooking Oil
Not all healthy oils behave the same way when heated. The key factor is the smoke point, the temperature at which the oil starts to break down and release harsh-tasting compounds.
- Avocado oil has the highest smoke point at 520°F, making it ideal for searing, stir-frying, and roasting at high temperatures.
- Olive oil varies by type. Extra-virgin has a smoke point around 350°F, which is fine for sautéing and medium-heat cooking. Regular (refined) olive oil can handle 390°F to 470°F. Despite being an unsaturated fat, olive oil is actually more stable during heating than many other oils.
- Flaxseed oil has a very low smoke point of just 225°F. It breaks down and goes rancid quickly, so it should be stored in the refrigerator and used only in cold applications like salad dressings or drizzled over finished dishes.
The same rule applies to walnut and grapeseed oil: polyunsaturated oils are less stable at high heat. Save them for dressings, dips, and low-temperature cooking.
What About Coconut Oil?
Coconut oil sits in an unusual middle ground. It’s technically a saturated fat, but about 47.5% of it is lauric acid, a medium-chain fatty acid that the body processes differently than the long-chain saturated fats in butter or beef tallow. Medium-chain triglycerides (MCTs) are absorbed more quickly and may be used for energy rather than stored as fat.
A recent systematic review found that diets enriched with pure MCTs led to modest weight reduction compared to diets high in long-chain fats. However, coconut oil itself is a mixture of medium- and long-chain fats, and the subgroup analysis showed that these mixed-length fat sources did not produce significant weight loss. Meanwhile, beef tallow, a long-chain saturated fat, was categorized as having “evidence of harm” due to its association with increased LDL cholesterol.
The practical takeaway: coconut oil is not the villain it was once made out to be, but it’s also not a health food in the way olive oil or fatty fish are. Using it occasionally for flavor is fine. Relying on it as your primary cooking fat means missing out on the proven cardiovascular benefits of unsaturated oils.
How Much Fat You Actually Need
The WHO’s current guidelines recommend keeping total fat at or below 30% of your daily calories. On a 2,000-calorie diet, that’s about 65 grams of fat. Within that total, saturated fat should stay under 10% of calories (roughly 22 grams), and trans fat should be below 1% (about 2 grams). The rest should come from monounsaturated and polyunsaturated sources.
A simple way to hit those targets without counting grams: cook with olive or avocado oil instead of butter, eat fatty fish twice a week, snack on a handful of nuts instead of chips, and add seeds to meals where you can. Those swaps alone shift your fat intake heavily toward unsaturated sources, which is where most of the measurable health benefits live.