The Four Dietary Guidelines
By Mr. L. N. Modi
1. Eat more vegetables, fruits and wholegrain bread and cereals : Increasing the amount of fruit, vegetables, whole grain cereals and pulses (lentils, beans and peas) you each day can also help to reduce your chance of developing cancer. That's because these foods contain essential nutrients and other important substances that may help your body destroy carcinogens before they can cause cancer. These foods are naturally low in fat, so eating lots of them instead of fattier foods is an easy way to reduce the amount of fat you eat. Also, as they are generally low in calories, they can help you to control your weight.
Some of the substances found in fruit, vegetables, whole grain cereals and pulses that are thought to help prevent cancer are beta-carotene, vitamin C, vitamin E, selenium, and dietary fiber. although these can also be purchased as supplements, taking them as pills is not a substitute for eating them naturally as part of food. We just don't know yet if it is these substances alone, or the whole foods in which they occur, that are responsible for helping to protect people against cancer. Fruit, vegetables, whole grain cereals and pulses contain hundreds of different compounds and we are just starting to examine them carefully for their ability to influence cancer development.
Vitamins : Beta-carotene is found in fruit and vegetables and is converted into vitamin A by the body. People who often eat foods rich in beta-carotene seem to have a lower risk of developing cancer, especially lung cancer, than those who don't eat these foods very frequently. Beta-carotene is plentiful in fruit and vegetables that are deep yellow-orange in colour, such as carrots, sweet potatoes, peaches, apricots, oranges, cantaloupe melons and bananas, and also in those that are very dark green such as spinach, spring greens and broccoli.
In laboratory studies, vitamin A in food appears to have protective effects against a number of cancers. Unlike beta-carotene, it can be toxic when taken in pill form well in excess of recommended amounts and should not be taken except under medical supervision.
Foods rich in vitamin C (also known as ascorbic acid) may protect against some.
2. Cut down the amount of fat in your diet, both saturated and unsaturated, from the current average of approximately 41% to a level of 30% of total calories.
The amount of fat that people eat in their diet has been linked again and again to their chances of getting chance. This is true in studies with humans around the world, and it is even true in numerous studies of laboratory animals. It seems to apply particularly to cancers of the breast, colon, rectum, ovary and prostate.
Breast cancer, for example, strikes women much more often in western, industrialized countries such as Britain where the typical diet contains a lot of fat. It occurs far less often among women in nations such as Japan and also in less industrialized countries where the standard diet is low in fat. Even in the United States, the Seventh-Day Adventists, who for religious reasons tend to eat more vegetarian and lower fat diets than the "average" American, are much less likely to suffer cancer of the breast of colon than other Americans.
In the current British diet, the major sources of fat are :
1. the visible fats, those we add to our foods such as butter, margarine, vegetable oils, cream and salad dressings, and
2. the less visible fats found in meat products, high-fat dairy foods, cakes, biscuits and other fatty snacks.
All of these fats together contribute about 42% of the calories which the average Briton consumes each day.
Why reduce fat to no more than 30% of total calories? : World scientific opinion recommends that we reduce consumption of fat from the current level of about 41% down to about 30% of the calories eaten. It is hoped that lowering fat consumption by that much will significantly improve the prospects for avoiding cancer. Actually, most of the research showing that reducing fat intake is linked to lower cancer risk is from comparisons of much greater difference in fat intake. However, such dramatic changes in dietary habits can be difficult. Thirty percent is a more realistic goal and a significant improvement, which most people in Britain can achieve without drastically changing their lifestyles.
Calculating the amount of fat as a percentage of the total calories we consume is a convenient way of specifying the level of fat in the diet of anyone, no matter what food they eat or how much of it, because all food contains calories. Calories are the energy in food and are provided by fats, carbohydrates and proteins. Gram for gram, pure fat contains roughly double the calories of pure carbohydrate or protein.
Cutting back on fat :
You can reduce the amount of fat in your meals if you follow some simple, general guidelines:
1. Reduce the amount of visible fats you eat:
* use less cooking oil and fat than suggested in recipes
* limit the use of butter, cream, salad dressings, margarine, oils and gravy
* bake, grill or boil rather than fry in fat.
2. Reduce the amount of less visible fats you eat:
* use low fat meat and low fat dairy products
* trim the excess fat from meat and the skin from poultry
* eat smaller portions of meat and dairy products
* eat fewer high fat cakes, biscuits and fatty snacks such as crisps and chocolate.
3. Eat lots of those foods which are naturally low in fat, such as fruit, vegetables, whole grain cereals and pulses (lentils, beans and peas). The more you substitute these foods for the fatty foods listed above, the less fat you will be eating.
You might also select individual foods with less than 30% fat. Here is how to tell which foods these are:
First, find the nutrition information on the packet. If the manufacturer doesn't give this information, don't buy the product (and write and tell the manufacturer why). The nutrition information should appear in a standard format, showing the number of kilocalories (or kcal, which is the same as calories) and the number of grams of fat per 100g of the product.
Look at the number of grams of fat and multiply it by 9 (the number of calories in a gram of fat) and divide the result by the number of calories. Multiply by 100 to get the percent of calories from fat.
Using a pocket calculator makes this much easier ! Carry one with you and check the labels as you shop.
You can use this formula to work out the percent of calories from fat in many packaged foods. Of course, don't think that you can only eat foods that are 30% or less fat. If you eat one food that is higher in fat, but eat fruit, vegetables or whole grain cereals with it, then the total fat content of the meal may still be at or below 30% of calories.
If you eat a whole meal which is high in fat, simply limit the amount of fat you eat at the next meal. Your main objective is to reduce the overall fat intake during the course of a day's or week's diet, week in, week out.
Saturated v Unsaturated Fat : While lowering the total amount of fat you eat is the most important for reducing your cancer risk, it may also make a difference what kinds of fat you include in your meals. Fats in food are saturated or unsaturated. Saturated fats tend to be solid at room temperature, while unsaturated fats are usually liquid.
Saturated Fat : Scientists are studying how saturated fats in our diets might promote tumour development and how lower amounts of saturated fat might lower cancer risk. Eating less saturated fat is also the main dietary recommendation to lower your risk of coronary heart disease, so you can kill two birds with one stone.
The Dietary Guidelines to Lower Your Cancer Risk state that you should reduce the amount of fat you eat to 30% of total calories and that about one third-i.e. 10% or less - should come from saturated fat.
How can you tell which foods contain saturated fats? Some products provide details of the saturated fat content on their labels, so be sure to read these and avoid products which don't give you this information. Beware of foods claiming to be "low" or "no cholesterol" - they may be high in saturated fat and total fat.
In general, fat in animal foods, such as meat and dairy products, is usually more saturated than fat from plant foods. The major exceptions to this are the "tropical" fats, coconut and palm oils, which are unusually high in saturated fats even though they are vegetable oils. Avoid products which list these oils as major ingredients and also those vegetable oils which have been artificially "saturated" with hydrogen - called "hydrogenated" oils or fats on the ingredients list.
Unsaturated Fat : You should also limit the amount of unsaturated fat you eat. There are two varieties of unsaturated fat, monounsaturated and polyunsaturated. Both are liquid at room temperature and found primarily in plant foods.
The main source of monounsaturated fat is olive oil. The major sources of polyunsaturated fats are the vegetable oils - corn, soya, safflower, sunflower and rapeseed. Certain oils from deep-water fish like mackerel, salmon and herring contain an unusual type of polyunsaturated fat made up primarily of omega-3 fatty acids. Some studies have shown that omega-3 fatty acids may offer some protection against cancer, but much more research is needed in this area.