Fat is the macronutrient with the widest sane range and the loudest arguments. EFSA’s reference intake range for adults is 20 to 35 per cent of total energy — which is to say, on a 2,000 kcal day, anywhere between about 44 and 78 grams. That is a span of nearly twofold, and it is deliberate: there is no single correct fat intake for a healthy adult.
The two fats you must eat
Inside that range sit the only two fats with an actual requirement, because the body cannot make them:
- Linoleic acid (LA), omega-6 — adequate intake 4% of energy.
- Alpha-linolenic acid (ALA), omega-3 — adequate intake 0.5% of energy.
Both are easy to hit. Rapeseed oil, sunflower oil, nuts and seeds cover linoleic acid without effort; rapeseed oil, walnuts, flax and chia cover alpha-linolenic. Deficiency in either is essentially a clinical curiosity in Europe.
Everything else about dietary fat is a question of proportion, not of need.
The two with no lower bound
EFSA lists both saturated fatty acids and trans fatty acids with the same instruction: “as low as possible” within a nutritionally adequate diet. There is no reference value because there is no requirement — the body synthesises all the saturated fat it needs, and trans fats have no function at all.
The WHO puts practical ceilings where EFSA declines to: no more than 10% of energy from saturates, no more than 1% from trans fats, for everyone aged two and over.
These are not in conflict. “There is no amount you need” and “here is a target a population can realistically hit” are answers to different questions.
The omega-6 panic, briefly
A recurring internet claim holds that omega-6 fats are inflammatory and that seed oils should be avoided. The regulatory position across Europe and the trial evidence do not support it: linoleic acid has an adequate intake set by EFSA precisely because it is required, and randomised trials replacing saturated fat with polyunsaturated fat show improvement in cardiovascular risk markers rather than harm.
The ratio of omega-6 to omega-3 gets cited a great deal. It is a weaker concept than it sounds, because a ratio can be improved either by eating less omega-6 or more omega-3, and only one of those has evidence behind it. Eat the oily fish; do not bother fearing the sunflower oil.
There is no safe lower limit for saturated fat and no upper reference value for linoleic acid. The internet has this exactly backwards.
What a 20% day and a 35% day look like
Both are fine. The difference is structural rather than moral.
A lower-fat pattern tends to be built on pulses, grains, lean protein and a lot of vegetables, with oil used as seasoning. A higher-fat pattern — think Mediterranean — leans on olive oil, nuts, oily fish and cheese, with less starch. Both land inside EFSA’s range; both can be built with saturates under 10% of energy; both have long-run evidence behind them when that condition holds.
What sits outside the range in practice is a diet where pastry, fried food and cheese push total fat past 40% with saturates at 15% — and one where fat is cut so aggressively that the replacement is refined starch. The second failure is the one the 1990s taught us, and it is the one the WHO’s replacement clause exists to prevent.
The one check worth doing
Look at the “of which saturates” line on the back of a pack, per 100 g, and compare it between two products you would otherwise buy interchangeably. Nothing else about dietary fat is as easy to act on, or as consistently overlooked.
