Fats, with the�proteins and carbohydates are macronutrients and the body's main source of energy. While carbohydrates are the first to be used up for this purpose, fats tend to be stored up waiting to be used. They also take part in some hormonal processes, satisfy the need for vitamines such as A, D and E -the so-called liposoluble ones- help build cell membranes. For all of these reasons, a balanced diet should include fats. The optimal level is a maximum 30% of the daily intake of calories. Going beyond this percentage can cause health problems and weight gain or even obseity.�

But some fats are healthier than others. First, we must distinguish between two major groups, saturated and non-saturated. Both are necessary, but the former only in small quantities. They are found in animal-based foods and tend to become solid at room temperature. It is proven that they tend to raise levels of cholesterol and thus the risk of suffering a cardiovascular disease. Non-saturated fats come from plants, and their effect on so-called bad cholesterol, known as LDL , is insignificant, although they do have a positive effect on levels of good, HDL cholesterol. Within this group there are mono- and polyunsaturated fats. The former� include olive oil, while the latter include seed-based oils such as sunflower and corn, as well as blue-meat fish and soy. Polyunsaturated fats include two essential acids, in other words ones that the body cannot manufacture on its own and must obtain in the food we eat. These are Omega 3 and Omega 6 fatty acids. We tend to consume more of the latter because they are part of vegetable oils, fish, dressings, mayonnaise and legumes, among other foods. Omega-3 fatty acids are� found mainly in blue-meat fish. In order to follow a proper diet it is important to get a balance between the two kinds of fatty acid. The proportion should be three to one.

How do we achieve the right level of fat consumption?
It might seem that we need to sit down at the table with a calculator and work out percentages. But in fact the task is much simpler.�

In the first place, it is always best to cook and season foods with olive oil, and keep in mind that raw, first-press oil is more nutritional. Secondly, choose vegetable fat over animal fat, and keep your intake of the latter to a minimum but without ruling them out altogether. It is also a good idea to eat a handful of nuts each day, raw if possible. They are rich in non-saturated fats. And don't forget about the blue-meat fish. Eat some at least three times a week. The ones richest in Omega-3 fatty acids are mackerel, tuna, bonito, sardines, anchovies and salmon. It is also essential to avoid foods whose fats have been hydrolyzed. This is a food processing technique that is considered very unhealthy. Products like vegetable margarine and industrial-style baked�goods are rich in this kind of fat.

Healthy fats both prevent and cure. On one hand they help keep cholesterol levels in check�and make arteries more elastic. In the case of Omega-3 fatty acids, research shows they reduce levels of triglycerides in the blood. They also strengthen the heart muscle and some studies suggest they protect against certain kinds of cancer, especially breast, colon and prostate. These fats help cure diseases like rheumatoid arthritis and Crohn's disease. Other studies show positive effects against asthma, psoriasis, lupus and atopical dermatitis.