The question in full

Q. I've read that margarine is bad for you as it is hydrogenated and so is high in trans fats. Is this correct?

A.  The short answer: If you live in Australia, no (with a couple of minor exceptions).

The long answer: Trans fats are formed when liquid vegetable oils are hardened or hydrogenated (treated with hydrogen) to turn them into semi-solid fats. Hydrogenation changes a fatty acid's molecular structure and turns a portion of the fat into the 'trans' form.

Trans fats made headlines

Trans fats really hit the headlines in 2008 with Governor Arnold Schwarzenegger banning them in California, the New York Health Department making restaurants and fast food outlets remove them as well as Denmark setting an upper limit on how much to be used. Now many products loudly trumpet "Free of trans fats" on their labels. For food companies, trans fats are useful:

• they can be made from cheap vegetable oils such as palm oil
• products made with them have a longer shelf life and keep well without refrigeration
• they produce biscuits and crisps with an attractive hard bite and pastries with a nice flaky texture.

Margarines are often associated with trans fats in consumers' minds, probably because they used to be the biggest source in our diet – but this changed in the 1990s because it became known that they're not good for our health. Manufacturers found the technology to make margarine without hydrogenation - which is the process that creates trans fats.

Now it's processed and take-away foods (chips, doughnuts, pies and pastries) that are the real problem. So trans fats are mainly found in commercial or industrial fats.

Margarines re-formulated

These days, margarine are in the clear in Australia. Australian manufacturers reformulated the majority of margarines or spreads to remove the trans fats back in the mid-1990s after research showed that they behaved much like saturated fats in the body, raising cholesterol and increasing heart disease risk. Today they typically contain less than 1 per cent.

Exceptions

The only exceptions are cooking margarines and a few of the cheaper or generic margarines, which have a firmness like butter and are hard to spread straight from the fridge. I suggest avoiding these hard ones. Choose the softer types instead – the ones you can spread straight out of the fridge.

The bottom line

When buying the softer spreads, here's how you can be sure you're not buying trans fat.  Simply look at the Nutrition Panel on the bottom of the tub – it should list trans fat as less than 0.1g per 100g or <0.1%.