Which cooking oil is healthiest?
There is no single healthiest oil, but there is a clear ranking by the fat inside it. Every pure cooking oil carries about 884 kcal per 100 grams[1], so this is not a weight question; it is a blood-lipid question. Olive oil is mostly monounsaturated fat, sunflower and corn oil are mostly polyunsaturated, and palm oil and ghee are half saturated fat or more[1]. The WHO guideline is to keep saturated fat under 10% of daily energy and to replace what you remove with unsaturated plant fat[2]. In practice: olive oil cold, a seed oil for frying, ghee as a flavouring.
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The calories are identical; the fat is not
Every bottle of pure cooking oil on the shelf holds about 884 kcal per 100 grams, whether it is olive, sunflower, corn or palm[1]. Ghee comes in a little lower, near 876 kcal per 100 grams, and only because a trace of water remains in it[1]. Swapping one for another therefore changes your energy intake by nothing at all, and an oil sold as a slimming food is being sold to you on a claim it cannot keep. If the calorie side is what you came for, that has its own article: how many calories are in a spoon of cooking oil.
What does differ between the bottles is the kind of fat inside them. That matters for blood cholesterol and for cardiovascular risk, not for the number on the scale, and it is the only sense in which one cooking oil is healthier than another.
What is actually in the bottle
A fat is described by how much of it is saturated, monounsaturated and polyunsaturated. The gaps between the common cooking oils are not small enough to be worth arguing about.
| Fat | Saturated | Monounsaturated | Polyunsaturated |
|---|---|---|---|
| Olive oil | 13.8 | 73.0 | 10.5 |
| Sunflower oil (standard) | 10.3 | 19.5 | 65.7 |
| Corn oil | 12.9 | 27.6 | 54.7 |
| Cottonseed oil | 25.9 | 17.8 | 51.9 |
| Palm oil | 49.3 | 37.0 | 9.3 |
| Ghee | 61.9 | 28.7 | 3.7 |
Grams per 100 grams of fat, from the USDA reference tables[1]. Two things stand out. Olive oil is overwhelmingly monounsaturated, which no seed oil is. And palm oil and ghee carry four to six times the saturated fat of sunflower or corn oil[1], which is the whole of the difference people argue about under the heading of taste.
What swapping one for another actually does
The World Health Organization's 2023 guideline asks adults and children to keep saturated fat below 10% of total daily energy, and makes a strong recommendation that what is removed be replaced with polyunsaturated fat, or with monounsaturated fat from plant sources[2].
That rests on trials rather than on observation alone. A Cochrane review of the long-term randomised evidence found that reducing saturated fat cut combined cardiovascular events by about 21% — a risk ratio of 0.79 across eleven trials and 53,300 participants — and that the size of the benefit tracked with what the saturated fat was replaced by[3].
The best-known trial on olive oil specifically randomised 7,447 adults at high cardiovascular risk. The group advised to follow a Mediterranean diet with extra-virgin olive oil had roughly 30% fewer heart attacks, strokes and cardiovascular deaths over a median of 4.8 years than the control group advised to cut fat, a hazard ratio of 0.69[4].
Read closely, none of this says olive oil is medicine. It says that unsaturated fat in the place of saturated fat is the lever, and that olive oil is the most convenient way most kitchens have of pulling it.
Frying is a different question from dressing a salad
Heat changes the comparison. The figure people quote is the smoke point, the temperature at which an oil visibly smokes; it is easy to measure and it is not what decides how an oil holds up. Stability under frying tracks the fatty-acid profile instead: fats low in linoleic acid and high in oleic acid degrade more slowly in a hot pan[5]. The double bonds that make a polyunsaturated oil useful at room temperature are the same ones that make it fragile at 180 degrees.
Reuse is the larger problem, and it is the one most home kitchens get wrong. In one controlled deep-frying experiment, the total polar compounds in the oil — the standard measure of how far it has broken down — climbed from 1.76% to 29.13% over 48 hours of frying, passing the 25% disposal limit at around 32 hours[5]. A household pan never sees 48 hours of service, but the direction is the point: oil that has been taken to smoking, or strained and poured back for a fortnight, is no longer the oil that was bought.
What this looks like in an Egyptian or Gulf kitchen
Almost all the fat in regional home cooking arrives from three places: a general-purpose vegetable oil for frying, olive oil for salads and cold dishes, and ghee for flavour in rice, pastry and eggs. Each of the three has a defensible place, and the places are not interchangeable.
- Olive oil anywhere it will not be heated hard: salads, drizzling, the last minute of a stew. It is the most monounsaturated of the everyday oils[1] and the only one with a large randomised trial behind it[4].
- A seed oil for the actual frying, used once or twice and then discarded. Sunflower and corn oil are both low in saturated fat[1]; their weakness is the heat and the reuse, not the bottle.
- Ghee and butter as flavouring, measured rather than poured. At about 62 grams of saturated fat per 100 grams[1], ghee spends a day's allowance faster than anything else in the kitchen.
That allowance is easier to respect in grams than in percentages. On the worked example the guides use, a 2,520 kcal day, holding saturated fat under 10% of energy[2] means roughly 28 grams, since fat carries 9 kcal per gram[6]. Three tablespoons of ghee come close to the whole of it on their own[1].
The short version
Use olive oil cold and at low heat, use a seed oil for frying and do not keep it long, and treat ghee, butter and palm-based cooking fat as flavour rather than as the base of a dish. Then stop thinking about the bottle, because how much total fat a day holds matters more than which oil it came from, and the guide on how to split your calories into carbs and fat sets out how that share is decided in the first place.
The practical move in a shared kitchen is to measure the fat that goes into the whole pot once, rather than negotiating with yourself at every plate. If you would rather have a second opinion on your own cooking than a general rule, an online nutrition coach on WhatsApp can read back what you actually cook with and where the saturated fat in your week is coming from.
Sources
- USDA FoodData Central, SR Legacy: Oil, olive, salad or cooking (171413); Oil, sunflower, linoleic (approx. 65%) (171025); Oil, corn, all purpose salad or cooking (171029); Oil, cottonseed, salad or cooking (171024); Oil, palm (171015); Butter oil, anhydrous (173412). ↩
- World Health Organization. Saturated fatty acid and trans-fatty acid intake for adults and children: WHO guideline. Geneva: WHO, 2023. ↩
- Hooper L, Martin N, Jimoh OF, Kirk C, Foster E, Abdelhamid AS. Reduction in saturated fat intake for cardiovascular disease. Cochrane Database of Systematic Reviews 2020;8:CD011737. ↩
- Estruch R, Ros E, Salas-Salvadó J, et al. Primary prevention of cardiovascular disease with a Mediterranean diet supplemented with extra-virgin olive oil or nuts. New England Journal of Medicine 2018;378(25):e34. ↩
- Romano R, Filosa G, Pizzolongo F, et al. Oxidative stability of high oleic sunflower oil during deep-frying process of purple potato Purple Majesty. Heliyon 2021;7(3):e06294. ↩
- Institute of Medicine (now NASEM). Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington DC: National Academies Press, 2005. ↩