Essential Fats of Life Historically, as income levels rise, and people are able to choose foods more on the basis of pleasure than what is locally available or affordable, the proportion of fat in the diet tends to rise. In some countries in Asia, it is estimated that fat makes up 40% of calories consumed. Experts agree that this is too high. High fat diets have been linked to many of the so-called lifestyle diseases, such as obesity, coronary heart disease strokes, and some cancers. Experts agree that limiting dietary fat intake, especially saturated fats is a priority health goal.


Facts and figures - the recommendations National guidelines vary (Thailand, Malaysia and Singapore recommend 20-30% of total energy, Indonesia, Japan and S Korea all recommend less than 25% ), but in the main, current research suggests that fat should make up a maximum of 30% of total energy content of the diet, and 25% is probably the most common dietary recommendation. For an adult consuming 2200 kilocalories a day, this might be translated in food items as 15 g of fat each for breakfast and lunch and 20 g for dinner, with 10 g for snacks between meals and drinks.


A sensible target for dietary fat intake would be no more than 30% of total energy from fat, made up of one third saturated, one third, monunsaturated and one third polyunsaturated.


Know your fats. Fat is the common name used to describe a whole family of compounds, including triglycerides, the phospholipids and sterols. About 95% of fats consumed in the diet are triglycerides. These may be visible (eg white fat on cuts of meat, cooking oils) or invisible (eg oils and solid fats used in bakery products, the oil in peanuts, coconut milk). All pure oils and solid fats, have the same calorific value. One gram of fat provides 9 calories of energy which is more than double the amount of calories for the same weight of carbohydrates or proteins. Chemically the triglycerides can be classified, according to their degree of saturation or hydrogenation: Fat molecules may be described as saturated, monounsaturated or polyunsaturated. In fact most foods contain a mixture of saturated and unsaturated fats, as the table overleaf illustrates


Low-fat or no-fat ? With all the information on the risks of a high fat diet, it might be easy to forget that fats are actually an essential part of the diet. Research has found that a healthy diet requires at least 15% of calories to be derived from fat. Fats are required for the efficient absorption of the fat soluble vitamins (vitamins A, D, E and K); and also the source of the 2 essential fatty acids which the body cannot manufacture itself. As long as the diet contains linoleic acid and linolenic acid, the two building block fatty acids, the body can manufacture all other omega-3 and omega-6 long chain unsaturated fatty acids that it requires. For this reason, these two substances are known as the essential fatty acids and the best source of these, are generally plant oils.


Recently there has also been a great deal of interest in possible health benefits from increased consumption of other non-essential fatty acids to boost the body?s own natural production levels. Most interest has focused on docohexanoic acid and eicospanetanoic acid (derived from oily fish such as herring, mackerel and tuna and some vegetable oils). Evidence is not conclusive, but benefits seem to include reduced risk of thrombosis (blood clotting), reduction of triglyceride levels (associated with reduced risk of heart disease and atherosclerosis) and improvements in visual and mental abilities. In summary, the omega-3 fatty acids from plant and marine sources, as well as the omega-6 fatty acids all have slightly different functions and a healthy diet will include rich sources of all three types of these polyunsaturated fatty acids. Fat is also an important source of energy and in a varied diet, helps to regulate appetite. Children under 2 years of age have relatively small appetites in relation to their energy needs, and should not be given low fat diets. Similarly anyone whose appetite is depressed or who finds it difficult to eat bulky foods may need to eat more fat than required by a normal healthy adult.


Food is for pleasure as well as health A no-fat diet would be very unpalatable. Fats and oils are an essential part of an enjoyable diet. Fats and oils bring important mouthtfeel and flavour to many of the foods we eat. The creaminess and smoothness of many foods is due to their fat content, the lightness of many baked products is based on the ability of fat droplets to trap air, the crunchiness of some foods is due to the ability of fats to be heated to very high emperatures. In addition, oils and fats are important carriers and blenders of many flavours and aromas, which make food appetising and help us to enjoy subtle combinations of flavours.


The cholesterol story The body manufactures cholesterol and it forms a necessary part of the body๛s cells. Some cholesterol in the body comes from food. However, the cholesterol from food does not automatically become cholesterol in the blood: Saturated and unsaturated fats in the diet have different effects on the cholesterol which is naturally present and circulating in the blood. We now know that saturated fats push up the LDL or bad forms of cholesterol, increasing the risk of heart disease and other cardiovascular diseases. Unsaturated fats decrease the bad LDL cholesterol, and increase levels of the healthy HDL cholesterol. Polyunsaturated fats have a slightly greater effect than the Monounsaturated fats. Those with elevated blood cholesterol levels definitely benefit from a low cholesterol, low saturated fat diet but for those with normal blood cholesterol levels, controlling the amount of saturated fat in the diet seems to more important than restricting cholesterol consumption.


The health benefits of monounsaturated fats Monounsaturated fats have a similar effect on blood cholesterol as polyunsaturated fats, but do not produce as many free radicals in the body. Free radicals are damaging to body cells and require antioxidant nutrients to neutralise their effects. Cold-pressed olive oil is rich in both monounsaturated oleic acid and antioxidants and these are thought to be two of the reasons for the health benefits of the traditional ๙Mediterranean diet๛. In fact, other oils also contain high levels of oleic acid and antioxidants. Plant breeding for example has resulted in the development of high-oleic safflower, sunflower, peanut, canola and soybean oils also.


The trans story There has been much concern about the effect of trans fatty acids on the body. Trans fatty acids are partially unsaturated fats. Their effect on the body is similar to saturated fats in that they raise total ?bad? LDL cholesterol and lower the ?good? HDL cholesterol. Trans fatty naturally occur in small amounts in some foods such as full fat milk and butter. Trans fatty acids are also found in ?shortening? fats, which have been hardened by a process, called hydrogenation. Hydrogenation is used to turn liquid polyunsaturated oils into solid fats in baked goods such as biscuits and pastries. Good quality argarines? with high levels of polyunsaturated fats contain very low levels of trans fatty acids.


Wise shopping choices can help The food industry has responded to concerns about rising dietary fat intake in many ways. Non-fat food ingredients such as emulsifiers and thickening agents have been developed to replace fats in some processed foods; improved hydrogenation processes have reduced the production of trans fatty acids; nutritional labelling enables consumers to monitor their own total and saturated fat consumption, and in some countries alternative lipids have been developed and marketed to actively reduce levels of ?bad? cholesterol in the blood. Consumers can use these innovations to their advantage : Choose low fat options, use information on labels, to check for total fat and proportions of saturated and unsaturated fats, or look at the lists of ingredients which are given in order of weight to check fat content.


Translating scientific knowledge into smart food choices Dietary guidelines around the region are based on research that aims to define optimal levels of nutrients we should eat in our daily diet. However, for consumers it is clearly not feasible to calculate nutritional values of all the foods bought, prepared and eaten. All foods are made up of a combination of nutrients and therefore all foods can be included in a healthy diet, but attention needs to be paid to the overall balance and variety. For this reason, many countries have now developed food based dietary guidelines, which provide a simple structure around which consumers can plan meals and daily eating patterns. The Low Fat Tips list below brings together advice from many countries in the region designed to ensure dietary fat intake does not exceed 25-30% of total energy intake, and there is a balanced, heathy mix of saturated and unsaturated fats.


Essential fatty acids dietary guidelines WHO recommends that essential fatty acids make up at least 3% daily calorie consumption. A varied balanced diet which includes some of the following rich sources of essential fatty acids provide all the body๛s daily requirements.


Polyunsaturated vegetable oils and margarines based on canola, soya, corn, safflower, sunflower, sesame, cottonseed, nuts and wholegrains, oily fish, lean meats, some leafy green vegetables, soyabeans and wheat germ.


Low Fat Tips Eat at least five portions of fruit and vegetables per day. Use low fat cooking methods such as grilling or baking instead of frying. Choose lean meats and trim all visible fat from meat before cooking. Choose low fat dairy foods. Use a variety of unsaturated cooking oils and spreads sparingly Check fat content on food labels. Choose high fat foods such as rich pastries, crisps and fried foods only occasionally. Choose oily fish such as tuna, herring, mackerel, and sardines twice a week and white fish regularly also. Eat a wide variety of foods. Include wholegrains, beans and nuts in your diet regularly (nuts are high in calories - so limit consumption ).