Foods high in fat — the type matters more than the amount

Fat is the densest energy source at 9 kcal per gram, and it does more than that. Every cell membrane is built from phospholipids, and the sex and adrenal hormones are made from cholesterol. Vitamins A, D, E and K are fat-soluble and absorb poorly without it, as do carotenoids such as the beta-carotene in carrots or the lutein in green peas. And two fatty acids are essential, meaning the body cannot make them and they must come from food: linoleic acid in the omega-6 family and alpha-linolenic acid in the omega-3 family.

The Daily Value on labels is 78 g. The recommendation used alongside it is to take 20 to 35% of total energy from fat, which on 2,000 kcal is 44 to 78 g. The guidance on type is more specific. The World Health Organization recommends keeping saturated fat below 10% of total energy and trans fat below 1%, and advises eliminating industrially produced trans fat from the food supply. The US Daily Value for saturated fat is 20 g; there is no Daily Value for trans fat, because the target is zero.

Bile emulsifies fat and pancreatic lipase breaks it down for absorption. The efficiency is high — over 95% — but food structure interferes. Fat in nuts stays trapped inside cell walls and a meaningful share passes through undigested, which is why measurements of almonds and pistachios put their real energy around 20% below the label. Oils, having no structure, are absorbed almost entirely. The same mechanism explains why fat-soluble vitamins and carotenoids absorb better alongside fat — dressing on a salad is not only about flavour.

This ranking shows the amount of fat and says nothing about the kind. A hundred grams of fat from olive oil and from butter are different foods, and that difference is not in this table. Replacing saturated fat with unsaturated fat is a clearer recommendation for cardiovascular risk than cutting fat in general. Trans fat is not a matter of moderation but of avoidance; look for "partially hydrogenated oil" on a label. And oil is extremely energy-dense — one tablespoon is 14 g and 124 kcal — so even a healthy oil is worth counting as you pour. Cutting fat too far affects fat-soluble vitamin absorption and hormones.