23/02/2026 - Gosia

Let’s talk about fat.

For years it was demonised. Now we’ve got “seed oils will kill you” videos, lard loyalists, olive oil purists, and keto warriors fighting in comment sections. It’s exhausting.

So, let’s look at what we actually know.

First of all, eating fat does not automatically make you gain body fat. Weight gain happens when you consistently consume more energy than your body needs, regardless of whether that energy comes from fat, carbohydrates, or protein. Fat is calorie-dense (9 kcal per gram compared to 4 kcal for carbs and protein), so it’s easy to overeat without realising. That’s the real issue. Not the molecule itself.

Fat is not optional. It plays a crucial role in hormone production, the absorption of fat-soluble vitamins (A, D, E, K), cell membrane structure, brain function and long term metabolic health. Extremely low-fat diets can negatively affect hormone levels, especially in women. Research suggests that consistently dropping fat intake very low – somewhere below roughly 15-20% of total daily calories – may impact endocrine function over time. So cutting fat aggressively to “lean out faster” is not a clever long term strategy.

Of course, not all fats are the same. We have saturated fats (like butter, lard, fatty meat, coconut oil), monounsaturated fats (olive oil, avocados), polyunsaturated fats (including seed oils like rapeseed/canola, sunflower, soybean, as well as omega-3s from oily fish and flax), and trans fats - which are the ones we genuinely need to be cautious about.

Let’s start with olive oil, because that one never seems to go out of fashion. Extra virgin olive oil remains one of the most studied fats in the world. Large observational studies and randomised trials supporting Mediterranean-style diets consistently associate it with reduced cardiovascular risk and better metabolic outcomes. It’s rich in monounsaturated fats and polyphenols, compounds with antioxidant and anti-inflammatory properties. The old idea that olive oil is useless for cooking because of a “low smoke point” is often exaggerated. Extra virgin olive oil is relatively stable thanks to its antioxidant content and is perfectly fine for normal home cooking temperatures. Buying it in a dark glass bottle is sensible, as it protects it from light and oxidation. Use it for salads, drizzle it over vegetables, cook with it - it’s not as fragile as the internet sometimes makes it sound.

Now to the controversial part: seed oils. Online you’ll hear that they are toxic, inflammatory, oxidised, modern poison. Current human research does not support the idea that moderate consumption of seed oils like rapeseed (canola) oil increases inflammation or causes disease in healthy individuals. In fact, replacing saturated fats with polyunsaturated fats has been shown in multiple meta-analyses to reduce LDL cholesterol and lower cardiovascular risk. Are seed oils refined and processed? Yes. Does that automatically make them harmful when used in reasonable amounts in the context of a balanced diet? No. The real issue is context. Deep-fried fast food repeatedly heated in industrial fryers is not the same as using a small amount of rapeseed oil at home. I use seed oils myself. The dose and the overall quality of the diet matter far more than the label.

What about lard and butter? Saturated fats are not poison, but higher intakes are still associated with elevated LDL cholesterol in many individuals. Mainstream UK and European guidelines continue to recommend moderating saturated fat intake and favouring unsaturated fats for cardiovascular health. Using lard occasionally is fine. Making it your primary fat source while ignoring vegetables and fibre is probably not the best long-term plan.

Then there are the keto enthusiasts. High-fat ketogenic diets can have specific clinical uses, and some people report good short-term weight loss results. But for the general population, extreme high-fat approaches are not required for health. You do not need to live in ketosis to be metabolically healthy. For most people, balance works better than extremes.

If there is one type of fat worth being cautious about, it’s industrial trans fats. These are strongly linked to increased cardiovascular disease risk in robust human data. Fortunately, in the UK and EU their use is heavily restricted, so they’re far less common than they used to be. Still, it’s worth checking labels for “partially hydrogenated oils” - that’s the red flag.

So, what should you actually buy? Extra virgin olive oil is a great everyday choice for salads and cooking. Rapeseed oil, ideally cold-pressed, is also fine for cooking. Oily fish provides omega-3 fatty acids. Nuts and seeds are excellent whole-food fat sources. Flaxseed oil is good used cold, never heated. Butter or lard can have a place occasionally, but they don’t need to be your main fuel source. You don’t need to fear seed oils. You don’t need to worship animal fat. You don’t need to drown everything in coconut oil because a podcast told you to.

What actually matters is your overall dietary pattern. A diet rich in vegetables, fruit, fibre, quality protein sources and reasonable amounts of fats will do far more for your health than obsessing over whether your oil came from a seed or a pig. Fat is not the enemy. But like anything calorie-dense, it’s easy to overdo. Balance, quality and context will always beat drama.