The low-fat diet craze that started in the 1990s should have made us all lean and cured America’s obesity epidemic. Unfortunately, it didn’t work.

Instead, we became so afraid of fat that we traded in traditional foods (full-fat dairy, butter, lard and even bacon) for man-made, low-fat versions (non-fat dairy, margarine or vegetable spreads, vegetable oils and meat alternatives). However, adding traditional fats back into your diet could actually make you healthier and leaner.

Yes, you read that right. Fat will not make you fat. A 2003 study from the Harvard School of Public Health showed that people who ate a high-fat diet lost more weight than those on a high-carbohydrate diet, even when the high-fat group ate 300 more calories per day.

Grains, processed carbohydrates and even fruit are all quick sources of fuel - any excess calories from those foods will be stored as fat.

By increasing your fat intake and lowering carbohydrates, you will allow your body to burn fat and use it for energy, rather than store it. There are nine calories in every gram of fat which makes it filling, too.

Fats play an incredibly important role in our health. They promote healthy cell function, help keep our bones healthy, enhance our immune systems and help us properly utilize essential fatty acids from foods like oily fish and grass-fed meat. They are also essential in the absorption of many vitamins and minerals, especially fat-soluble vitamins A, D, E and K.

There are even some saturated fats - which are typically demonized - that are healthy. Those found in coconut oil, lard and butter function as signaling messengers that influence metabolism and can speed up weight loss.

But not all fats are created equal. Trans-fats and 'partially hydrogenated' fats from processed foods are highly refined and should be avoided because they don’t provide any health benefits.

When choosing animal fats, look for organic sources that have been pasture-raised. Animals that have been raised on grass will have high levels of omega-3 fatty acids, which aid weight loss while promoting a healthy immune system.

By making only two simple changes, you can improve your health and encourage your body to burn more fat. Always check with your doctor before making any significant changes to your diet.

Use butter.

According to Dr. Mary Enig, author of Know Your Fats, consuming the trans fatty acids found in margarine can increase blood insulin levels, which may increase risk for diabetes.

However, butter from pastured cows is high in vitamins A, D, E and K and rich in conjugated linoleic acid, which has been shown to prevent weight gain and encourage muscle growth.

Another great component of butter is butyric acid, which has been shown to help fight cancer. An easy rule of thumb to remember which butter to buy is to look for brands from New Zealand, since they are all pasture-raised.

Cook with coconut oil.

Vegetable oils are extracted from the seeds of soybeans, corn, sunflower and rapeseed (canola). The oils must be chemically removed, deodorized and altered before being used and were practically non-existent in our diets until the early 1900s.

Instead, try coconut oil, which is made of medium-chain triglycerides that are processed through the liver. It provides energy without causing insulin to spike. It is high in lauric acid (also found in breast milk) and also contains capric acid and caprylic acid, which provide excellent antioxidant, antibacterial, antifungal, antiparasite and antiviral properties.

A study conducted by the American Journal of Nutrition found that consuming 2 tablespoons of these medium-chain fatty acids can cause a rise in body temperature after a meal, leading to an increase in metabolism and a greater calorie burn.

Making these simple changes can help you get lean, provide you with more nutrients and boost your immune system - all while making your food taste delicious!