trans-fats and which oils to use for cooking?

[inconceivableme]

A friend says that roasting / baking / frying with any vegetable / olive / soya / sunflowers oils is unhealthy due to trans-fats. Apparently it's healthier to use (expensive!) coconut oil, fat from roasted meat or butter?! But aren't these v unhealthy - cholesterol etc? If all vegetable
oils are so bad, maybe someone should tell the NHS website, Jamie Oliver and everyone in the Mediterranean?

Not all the oils you mention are transfats. But yes, upon heating the structure can change and be not too great for your health.

But - olive oil, rapeseed and sunflower oils aren't bad if not heated to a high temperature.

Butter and lard are are fine to cook with - as they don't contain any hydrogenated fats. These are the dodgy fats in baked goods, margarine type spreads etc.

Basically the best thing is to not fry anyway. Avoid cakes and biscuits and chocs and eat natural.

The NHS website is notoriously bad at advice -promoting low fat this, high carb that.

Your friend is wrong. Transfats are artificial, highly modified fats that used to appear (and increasingly don't) in processed, long-life products.

All oils and fats have various 'flashpoints' which is the temperature they burn at. Eating burnt fat of any description is not recommended. Rapeseed, sunflower and avocado oil, for example, have very high flashpoints and are good for high temperature cooking - stir-fries etc. EVOO and butter have much lower flashpoints so gentle heating is in order.

It is recommended to consumer fewer animal fats in general whether that's from meat or dairy products. Because animal fats solidify at low temperatures, reducing their consumption helps reduce blood cholesterol believed to be a factor in heart disease. Nutritionally, small amounts of animal fats are beneficial - D vitamins, B vitamins etc. Palm oils and coconut oils perform rather like animal fats and are best kept to a minimum. Most vegetable oils, by contrast, remain liquid and also contain Omega fats, Vitamin E and other nutritional elements.

Reducing total fat in the diet is still a sensible suggestion as fat is highly calorific and energy dense. As ever, aim for a balance.