“Eat fat to get slim, don't fear fat, fat is your friend. It's now truly time to bring back the fat”. This is the message from the Public Health Collaboration, a group of medics who have issued a report saying that avoiding fat is bad for our health.

Dr Aseem Malhotra, consultant cardiologist and founding member of the Public Health Collaboration, says dietary guidelines promoting low-fat foods “is perhaps the biggest mistake in modern medical history, resulting in devastating consequences for public health”.

“Sadly this unhelpful advice continues to be perpetuated. We must urgently change the message to the public to reverse obesity and Type 2 diabetes,” he adds.

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But we’ve been told for years that we should steer clear of fat, so why are we now being told otherwise?

Does fat make us fat?

No, according to leading nutritionist Dr Marilyn Glenville, who says: “Forget the myth that fat is fattening; it is sugar and refined carbohydrates that make you fat.

“Sugar is nothing more than empty calories - it gives you no nutritional value. Think of insulin as the ‘fat hormone’ of your body. When it’s released, it directs energy from food into storage. So the more insulin you produce, the more your food’s likely to be stored as fat.

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“Unfortunately, when insulin levels are high, your body doesn’t use fat for fuel. It uses the glucose in your blood instead. So when insulin is being produced, you won’t lose weight; your body will cling onto your fat stores,” says Glenville.

However, eating too much of anything can, in theory, lead to weight gain, says nutritionist Cassandra Barns. “Excessive intake of either fat or carbohydrates can lead to weight gain, simply by providing more calories than the body needs,” she says.

“But this doesn’t mean fats should be avoided altogether, otherwise we could run into health problems. The key is to get enough of the healthy types of fats, while avoiding those that are more likely to cause problems.”

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Do we need fats?

Absolutely – our body needs fat to function. “Fats are needed for all our cell membranes, providing a fluid structure to let substances in and out of the cell, while maintaining its shape,” says Shona Wilkinson, nutritionist at SuperfoodUK.com.

“They’re vital for our brain too: about 60 per cent of the dry weight of the brain’s made up of fat, including the omega-3 fat DHA, found in oily fish. DHA is needed for vision too.

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“Fats also allow nerve signals to pass around the body properly, as they make up a substance called myelin that insulates nerve cells. Many of our hormones are made from fats, and we even need fats to absorb vitamins such as vitamin A, vital for immunity and eyesight, and vitamin K, which supports bone health and healthy blood clotting.”

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Good fats vs bad fats

Not all fats are made equal, however. As Wilkinson advises: “There are ‘good fats’ such as the omega fatty acids, and there are ‘bad fats’, such as hydrogenated fats, often found in processed foods, that are full of damaging trans-fatty acids.

“We’ve also been told in the past to avoid saturated fats (found in foods like milk cheese, meat, coconut oil and cocoa butter) because they can cause heart disease, but more and more research is emerging that’s found they do not. 

“When food companies create low-fat food, they remove the fat and replace it with sweeteners, artificial flavourings and additives. It does not necessarily make the food healthier.”

Dr Glenville adds: “With no nutritional benefits at all, trans fats are the worst fats and should be avoided at all costs. Found in many processed foods to prolong shelf life, they might appear on the label as hydrogenated or partially hydrogenated vegetable oil. Trans fats are linked to an increase in heart disease and are terrible for general health, as they harden cells and arteries. They also cause fat to gather around the mid section, even if you’re sticking to low calorie diet.”

Will you be eating more good fats from now on? Tell us in the comments section below.