What are seed oils? The complete list

Every cooking fat, ranked worst to best

PUFA as a share of total fat, USDA data. The higher the bar, the more seed oil load every tablespoon carries. Real fats at the bottom are what restaurants fried in for most of the last century.

Grams shown are per tablespoon of pure oil (13.6g of fat). See any two side by side on the oil vs oil pages.

The 8 seed oils people avoid

1. Canola (rapeseed) oil. The most common restaurant oil. Cheap, heavily refined, very high in PUFA.
2. Soybean oil. The number-one oil in the American diet, often hidden as "vegetable oil."
3. Corn oil. A refined, high-PUFA oil common in frying and processed food.
4. Sunflower oil. High in PUFA unless it is a "high-oleic" version, which is more stable.
5. Safflower oil. Among the highest-PUFA oils of all.
6. Cottonseed oil. A byproduct oil used in frying and shortening.
7. Grapeseed oil. Marketed as gourmet, but very high in PUFA.
8. Rice bran oil. Refined and high in PUFA; common in Asian fast food.

On a label, watch for "vegetable oil," which is usually soybean or canola, and any oil above that is not olive, avocado, coconut, butter, ghee, or tallow.

How to spot seed oils on a label

Labels rarely say "seed oil." Here is what the same ingredient looks like in the wild:

1. "Vegetable oil." Almost always soybean, canola, or a blend of both. There are no vegetables in it.
2. "Shortening" or "margarine." Seed oils processed to be solid. Most commercial baking uses one of these.
3. "Plant-based oil blend" / "cooking oil." Restaurant menus use these when the fryer oil is a commodity soy or canola blend.
4. "High-oleic" sunflower, safflower, or canola. Bred to be lower in PUFA — genuinely less of the problem fat, but still a refined seed oil.
5. Soy lecithin. An emulsifier, not an oil. Gram for gram it adds almost no PUFA — most people tracking seed oils ignore it.

Rule of thumb: if the fat is not olive, avocado, coconut, palm, butter, ghee, tallow, or lard, treat it as a seed oil until proven otherwise.

Where seed oils actually hide (our data)

We maintain oil records for 558 US chains and PUFA estimates for about 57,000 US menu items. As of August 2026:

1. 536 of 558 chains with a verified oil record — 96% — cook with seed oils. Only 22 have no seed oil in their record at all, and just 9 of those cook exclusively in traditional fats like butter, tallow, or olive oil. Tallow Watch tracks the holdouts.
2. The fryer is the problem, not the protein. Across our dataset the median order of fries carries 10g of PUFA and the median fried-chicken item 11g, versus 7g for a burger, 5g for a salad, and 0g for a drink. The worst tenth of fries hit 16g or more — from the oil, not the potato.
3. Independent restaurants are usually worse than chains. The big food distributors that supply them fry America in soybean oil by default — see the distributor breakdown.
4. Baked goods are the quiet source. Nearly every commercial pastry, bun, and cookie is made with soybean-oil shortening. It does not need a fryer to add up.

Every number is an estimate, clearly labeled, and recomputed as chains change oils. Full methodology here; the whole dataset is a free download.

How seed oils took over

For most of history, cooking fat came from animals or fruit: tallow, lard, butter, olive oil. Seed oils are new. Cottonseed oil was a waste product of the cotton industry until Procter & Gamble turned it into Crisco in 1911. Soybean oil scaled after World War II as a byproduct of soy meal for livestock. Canola was engineered from rapeseed in 1970s Canada. The last domino fell in 1990, when US fast-food chains under pressure over saturated fat switched their fryers from beef tallow to vegetable oil — McDonald's fries included. Restaurants stay with seed oils for one reason: a jug of soybean oil costs a fraction of tallow or olive oil at fryer volumes.

Are seed oils actually bad for you?

Honest answer: it is contested, and both camps overstate their case. What is not in dispute: seed oil consumption rose from roughly zero to the single biggest source of fat in the American diet in about a century, the linoleic acid stored in our body fat has roughly doubled since the 1960s, and PUFA is the least heat-stable fat in the fryer — repeated frying produces oxidation products that stable fats do not. What is debated is how much that matters for long-term health, and mainstream nutrition bodies still consider these oils safe. Our position: we do not tell you what to eat, we show you the grams and let you decide your own ceiling. Read the studies on both sides, or sign the petition for fry-oil disclosure.

How to actually avoid them

1. At home: cook in butter, ghee, tallow, olive, avocado, or coconut oil. The swaps guide covers the pantry staples that usually hide seed oils (mayo, dressings, "vegetable oil" sprays).
2. Eating out: pick the chain first — the gap between an A-graded chain and an F-graded one is bigger than anything you can fix by ordering carefully. Then skip the fryer items. The full playbook is in our eating-out guide.
3. Check before you order: every chain has a report card — the grade, the frying oil, the safest orders, and the items to avoid, for the US plus Canada, the UK, and Australia.