Fat spent decades as the villain of the diet world, which is how supermarket shelves ended up full of low-fat everything. Nutrition science has since moved on: fat isn’t the enemy, it’s an essential macronutrient the body can’t function without. The real question isn’t whether to eat fat, but how much and what kind.

How much fat you actually need

Most mainstream dietary guidelines suggest fat should make up roughly 20-35% of total daily calories. For someone eating around 2000 calories a day, that works out to about 45-78 grams of fat. The right number within that range depends on age, activity level, overall health, and personal goals — some people do better near the lower end, others near the higher end.

It’s worth remembering this is a range, not a ceiling to avoid. The body needs fat to absorb fat-soluble vitamins A, D, E, and K, to produce hormones, and to keep cell membranes functioning properly. Cutting fat too aggressively for too long can lead to deficiencies in those vitamins and show up as dry skin or brittle hair.

Not all fats are created equal

The bigger issue is usually quality, not quantity. Saturated fat, found in fatty cuts of meat, butter, and certain cooking fats, is generally recommended to stay under about 10% of daily calories. Regularly eating more than that is linked to higher blood cholesterol and increased cardiovascular risk over time.

Unsaturated fats — both monounsaturated and polyunsaturated — are the ones nutritionists want making up the bulk of your fat intake. They’re abundant in olive oil, other plant oils, avocado, nuts, seeds, and fatty fish. Trans fats deserve a separate mention: they form when vegetable oils are partially hydrogenated, and they show up in some margarines and commercially baked goods. These are the fats worth minimizing altogether, since they carry the clearest downside for heart health.

Omega-3 and omega-6: balance matters

Among polyunsaturated fats, omega-3 and omega-6 fatty acids get particular attention. Omega-6 is plentiful in most vegetable oils and shows up in typical diets without any special effort. Omega-3 is the one people tend to fall short on — its best sources are fatty fish like salmon, mackerel, and sardines, along with flaxseed, chia seeds, and walnuts. Nutrition experts generally recommend working omega-3 sources into meals a couple of times a week, since these fats play an important role in heart and brain function.

What the norm looks like in practice

Hitting a reasonable fat target doesn’t require counting grams. A few practical habits get most people there:

• Cook and dress salads with plant oils instead of leaning heavily on butter or margarine.
• Work in sources of unsaturated fat — nuts, seeds, avocado, fatty fish — several times a week.
• Don’t shy away from naturally fat-containing whole foods like eggs or plain yogurt; in sensible portions they fit comfortably within a healthy range.
• Keep an eye on foods likely to contain trans fats: packaged baked goods, certain margarines, and fried fast food.

Why low-fat diets aren’t always the answer

The low-fat craze of the 1990s has largely been reconsidered. Cutting fat out completely often just makes room for more refined carbs and sugar, which rarely helps weight or overall wellbeing. Fat also contributes to satiety and makes food taste satisfying, so having a reasonable amount in your meals can actually help you avoid overeating elsewhere.

The takeaway is simple: fat isn’t something to avoid, it’s something to choose thoughtfully. A good mix of unsaturated sources, moderation with saturated fat, and minimal trans fat cover most of what matters, without needing to track grams at all.