Fats - The Alternative Energy Source
Fat is a very concentrated source of energy providing more than double the calories of carbohydrates and protein (about 9 calories per gram). It performs many important jobs within the body – it is vital for the structural integrity of all cells, gives insulation against cold, provides physical protection to the delicate organs such as the kidneys, is vital for repair and regrowth of brain and nervous tissues, is fuel for the brain, heart, nerves and secretory glands, serves as an internal heat source, acts as a carrier for fat soluble vitamins and provides a good source of energy to all the cells in the body.
When fats are digested they are broken down into their simplest form – fatty acids. Fatty acids can be classified as saturated, monounsaturated and polyunsaturated. Saturated fats are usually solid at room temperature, the major source of which are animal products (meat and dairy produce), the major plant sources being coconut and palm oils.
The mono and poly unsaturated fats are generally liquid at room temperature (oils) and are exclusively vegetable in origin. However many vegetable oils are ‘hydrogenated’ by the food industry and added to products such as cakes, pastries, biscuits and margarines. Hydrogenation renders a liquid oil more solid and also turns it from a mono or polyunsaturated oil into a saturated one. There is growing evidence that these adulterated oils are devastating to health and may be responsible for the occurrence of many chronic diseases. Another important feature of oils is that once harvested from their plant source they quickly become rancid. The rancid oils act as 'free radicals' within the body, stealing oxygen from the tissues and attacking and damaging cell structures causing, over time, generally poor health and premature ageing. The only exceptions to this rule are the cold pressed (unrefined ) oils. To avoid the effects of free radical damage from processed oils it is sensible consume the oil as nature intended it – by eating the whole food in which the oil is contained e.g. eat sunflower seeds instead of using the refined oil, or use only pure unrefined oils. Heating oils also changes them further so it is best to use them raw, drizzled over food after it has been cooked.
As with the essential amino acids in protein there are also essential fatty acids (e.f.a.s) that cannot be manufactured by the body so need to be provided in the diet, examples would be Omega 3 and Omega 6. These are important for a healthy body and play a vital role in the prevention of heart and circulatory diseases, cancer, mental illness, allergies and immune disorders to name a few. They oxygenate the cells, provide nourishment to the tissues and can actively help remove unwanted deposits from arterial walls.
Fats provide their energy in a different way from carbohydrates. Fats are stored as energy reserves in far greater quantities than glucose. For example, glucose will provide enough energy for 1 day if no food is eaten (about 600 kcals), whereas stored fats can provide enough energy for the body for up to 40 days with no food eaten (about 100,00 kcals!). When carbohydrate intake is low and the body begins to use fats as its main source of energy, ketones or ketone bodies are produced. Ketones are the preferred fuel of both the brain and heart which is interesting when you consider that ketones are only produced when carbohydrate supplies are low. This seems to strongly imply that a low carb diet rich in healthy, unprocessed fats and proteins is better for health than a low fat, high carb diet.
SOURCES OF FATS AND OILS
MEAT AND ANIMAL PRODUCTS
SEEDS are a rich source of mono and polyunsaturated fats and are very low in saturates. Linseeds for example contain high amounts of Omega 3 ( 60% ) and Omega 6 ( 20% ) essential fatty acids as well as compounds which are anti-viral, anti-fungal and anti-cancer. Hempseeds contain 30% fat, of which 20% is Omega 3 and 60% is Omega 6 and contains many other important minerals and nutrients. Eating a combination of sunflower, sesame and pumpkin seeds is reputed to provide a good balance of e.f.a.s. Other seeds containing oils which are useful include blackcurrant, mustard, aniseed, fennel, cardamon, cumin, grape, fenugreek, evening primrose. Many of the oils present in the seeds contribute to lowering blood cholesterol levels.
VEGETABLE /'COOKING' OILS as mentioned earlier are best when in their unrefined and raw state. Walnut, sunflower, safflower, grapeseed and hazelnut oils are all suitable for use on salads or as dressings. The finest oil however is extra virgin olive oil. It does not go rancid and is an excellent carrier and preservative for herbs and spices to be macerated in. It is a prime anti-oxidant (destroys free radicals), actively protects the heart, balances blood cholesterol and cleans the liver and gallbladder. It is the most stable of all the oils when heated but is more beneficial when raw.
NUTS are all high in fats and oils, especially macadamia. Other good nuts include peanuts, brazils, cashews, almonds, hazelnuts and walnuts which contain large amounts of essential fatty acids.
Oats, Avocados, Olives, Beans and many other vegetables contain smaller traces of oils including Carrots.
