Fats and Health

There are three types of fat: saturated, polyunsaturated and monounsaturated. All fats are a mixture of these, but health dangers or benefits are determined by which type predominates, and in some cases by food-manufacturing processes.

Heath authorities recommend that we eat less fat overall and focus on the healthier kind.

The bad fats: The less we eat of these the better! Saturated fats

• Dairy and meat products are the major source of saturated fat in the Western diet. Products made from whole milk or cream, such as butter, dairy ice-creams and most cheeses, are particularly rich sources.

• Coconut and palm oils (often called tropical oils), used in some canned and processed foods, are also mainly saturated. Avoid these and 'blended vegetable oils', which often contain them.

For years health experts have rated saturated fat, which raises cholesterol in the blood, the single greatest danger in the Western diet. A truly vast quantity of evidence links it with clogging the arteries with plaque, which impedes blood flow to the heart and brain, leading to heart disease and strokes.

Growing evidence also links saturated fat with breast and prostate cancer. Initial findings from the most definitive diet-and-cancer study ever conducted, the European Prospective Investigation into Cancer and Nutrition, indicate that women who eat too much dairy fat and meat double their breast-cancer risk. This current study of half a million people in ten European countries has real import, unlike so many of the small or badly designed studies publicized these days. Other recent studies reveal that breast cancer has doubled in Japan since the younger generation adopted a Western diet.

Trans fats

• These lurk in some margarines and fat spreads, in many readymade goods such as biscuits, cakes and crisps, and in most deep-fried fast foods.

Trans fats are made when manufacturers solidity vegetable oils to make margarine by using hydrogen. They are as dangerously artery-clogging as saturated fats, possibly even more so. If the ingredients list on a food label contains the word 'hydrogenated', the product is likely to contain trans fats. Avoid margarine-type spreads which state 'hydrogenated' or 'partially hydrogenated'. Choose those like Flora on which the labels state 'no trans fats' or 'non hydrogenated'.

Hydrogenated oils are used in so many manufactured foods that they are very hard to avoid completely. But F2's Fat and Calorie Controller will prove a boon in showing you how to ration or screen out those with a high content.

The Good Fats: Focus on these fats particularly when you are rationing fats to weight-loss level.

Polyunsaturated fats supplying essential Omega 3 fatty acids

Richest sources are oily fish mackerel, herring, sardines, anchovies, tuna, trout and salmon. Wild fish tends to be a better source than fanned fish.

Richest plant sources are flaxseeds, walnuts and their oils.

Omega 3 free-range eggs are now sold in major stores and one egg can provide a half to two-thirds of the recommended daily amount of Omega 3.

The polyunsaturated fats are not cholesterol-raising or artery clogging and we need a small quantity of them to supply essential fatty acids. There are two types of these, Omega 3 and Omega 6. We're unlikely to go short of Omega 6, but nowadays we lend not to eat enough Omega 3. This is suspected of being a causal factor in heart and other major health problems.

As a result of raised awareness, Omega 3 eggs probably the easiest way to ensure you get enough or this nutrient have become widely available in the supermarkets, and you can choose from a whole range of flaxseed oils, or, better still, flaxseeds themselves, in health-food shops. But remember that even oil rich in Omega 3 is high in ca lories. Choose fish in preference to meat, but go easy on oily fish, both on account of the calorie score and concerns about its content of potentially harmful substances called dioxins.

Monounsaturated fats: Richest sources are olive oil, rapeseed oil (canola), peanut oil and the oil in avocados.

Monounsaturated fats are even more healthy than polyunsaturated fats. They lower cholesterol to the same extent but also distribute it in the blood in a healthier way. Olive oil has a particularly high content of saturates.

Rapeseed oil is almost as good. The widespread use of olive oil, along with low meat and dairy intake and the consumption of large quantities of fruit, veg, grains and fish, lies behind the famed health benefits of Mediterranean diets.