For decades we were told that eating fat would clog our arteries and send us to an early grave, but a current study published in a leading medical journal disproves this theory.

In fact, fat may be good for us. A mounting slew of evidence suggests that having full dairy in your diet may actually protect you from heart disease, cancer and Type 2 diabetes.

The study, published in the American Journal of Clinical Nutrition, found overweight middle-age men who ate high levels of saturated fats - mainly found in dairy, meat and tropical oils - and low levels of carbohydrates lost weight.

A new study says people stop counting calories and eat healthy fats like butter, cream, cheese

Besides a slimmer figure, the men's blood pressure and glucose levels were reduced. Refined carbohydrates turn into sugar in our bodies, causing a spike in insulin that leads to fat accumulation in cells, experts say.

Professor Sherif Sultan, a heart specialist from the University of Ireland, told the Sunday Express: 'We urgently need to overturn current dietary guidelines.

'People should not be eating high carbohydrate diets as they have been told over the past decade.

Some of the most nutritious foods available are meat, eggs and dairy products, experts say

'Instead our diets should be largely based on good quality high-fat foods. This will prevent the rising epidemic of Type 2 diabetes and reverse the growing numbers of people suffering weight-related heart problems.'

The roots of the obesity epidemic lie in diets high in carbohydrates and sugars, Professor Sultan said.

Eating a diet rich in full-fat dairy may help lower the chance of obesity. However, researchers stress that there's a distinction between types of fat.

HEALTHY FATS AND WHY THEY ARE GOOD FOR US A small amount of fat is an essential part of a healthy, balanced diet. Fat is a source of essential fatty acids such as omega-3 – 'essential' because the body can't make them itself. Fat also helps the body absorb vitamins A, D and E. There are different types of fat and some are better for us than others, the Government claims. To cut the risk of heart disease, the Government recommends cutting the amount of saturated fat - found in meat and dairy products - with unsaturated fat. Monounsaturated fats - such as those found in avocado, olive oil and nuts - help protect our hearts There is good evidence that replacing saturated fats with unsaturated fats can help lower cholesterol, it says. Found primarily in oils from plants, unsaturated fats can be either polyunsaturated or monounsaturated. Monounsaturated fats help protect our hearts by maintaining levels of HDL cholesterol while reducing levels of LDL cholesterol. Monounsaturated fats are found in: olive oil, rapeseed oil and their spreads

avocados

some nuts, such as almonds, brazils and peanuts There are two types of polyunsaturated fats: omega-3 and omega-6. Some types of omega-3 and omega-6 fats cannot be made by the body and are therefore essential in small amounts in the diet. Omega-6 fats are found in vegetable oils such as rapeseed, corn, sunflower and some nuts. Omega-3 fats are found in oily fish such as mackerel, kippers, herring, trout, sardines, salmon and fresh tuna. Polyunsaturated fats can help lower the level of LDL cholesterol. Too much LDL cholesterol can lead to fatty deposits developing in the arteries, which can restrict the flow of blood to the heart and brain, increasing the risk of heart disease and stroke. Replacing saturated fats with polyunsaturated fats may also help reduce triglyceride levels. Triglycerides are fatty substances mostly made by the liver. High levels of triglycerides in the blood have also been linked with narrowing of the arteries. Source: NHS Choices Advertisement

The men in the study were given 'good fats', such as unprocessed butter cream and cheese that scientists believe absorb well in the body.

Dr Simon Dankel, associate professor at the University of Bergen in Norway, which carried out the study, said: 'There is a tremendous focus on avoiding high-fat foods for weight control but this study challenges the notion that saturated fats have a strongly negative impact on health and weight.