By Caroline Rechia • August 2nd, 2006 • 3917 Views
Fat gets a bad rap. It's an unfair one, too, because fats are one of 4 key nutrients that we need to survive. In order of volume they are water, carbohydrates, proteins and fats. When a healthy person eats a naturally-occurring fat, it gets broken down into small units used to build cell membranes and tissues, to cushion organs and keep us warm. Fat is also used by our cells to make important hormones. It's also a great source of energy with each gram of fat providing 9 calories, whereas carbohydrates and proteins only provide 4 calories per gram.
Fat can either be eaten in our diet or manufactured in the body from other materials but 2 fats in particular are essential. That is, we need to eat these fats because our body cannot make them. These fats are Omega 3 and Omega 6, also known as essential fatty acids (EFAs).
Dietary fat in our diet is classified in ways that may sound familiar. They are either saturated fat (animal fats and others such as avocado which are solid at room temperature), monounsaturated fats such as olive oil or polyunsaturates which are unstable fats sourced from plants and some cold-water fish. Omega 3s and 6s fall into the polyunsaturated category and this means that their molecular structure is ready to accept hydrogen atoms. Being exposed to, and accepting hydrogen would create a molecular change for these fats and so we call them unstable. They are best when kept protected from light, heat and air: kept in a dark, airtight container in the fridge.
What about transfats? Some transfats naturally occur in small amounts in animal foods, but most are made artificially when trying to make shelf-stable solidified fats out of liquid polyunsaturated oils, as is the case with margarine. These oils are forced to artificially accept hydrogen atoms by adding metal particles to the oil and spraying it with hydrogen at high temperatures. Transfats have been linked to ill health and specifically heart disease....