Sensible Eating (part II)

Reasons for minimising or excluding

Recreational drugs

This might seem obvious as a suggestion for a pregnant woman, but it is nevertheless worth emphasising. Once you know you are pregnant it is very wise to avoid all recreational drugs—including alcohol. The most important reason is that in developed countries, folate deficiency is often linked to excessive consumption of alcohol. Alcohol limits the absorption of this vitamin. Inadequate folate is definitely associated with neural tube abnormalities in the foetus (producing disorders such as spina bifida) and might well be associated with miscarriage. A list of foods containing folate can be found below.

Another reason for our strong recommendation against the use of recreational drugs during pregnancy is the increased likelihood of various other birth defects. Apart from alcohol, recreational drugs include tobacco, stimulants of various kinds, marijuana, and other non-prescription drugs.

You should also check all prescription drugs with your doctor to make sure that these drugs pose no threat to the developing foetus.

Tea and coffee

Green teas, in particular, have been found to be good sources of various antioxidants. This is good news if you like tea! However, tea is a mild diuretic (that is, it causes the body to lose water), so make sure that you have your tea reasonably weak and have a glass of water for every cup.

Coffee, unfortunately, doesn’t seem to have any benefits according to many researchers—unless you count its great taste! If you consume too many cups (usually reckoned at more than three per day) you will encounter one of the disadvantages of this drink—too much caffeine. This can make you irritable and can make your hands tremble. Coffee, depending on the strength, is a stronger diuretic than tea, so have a glass of water with every cup you drink to offset this effect.

Anecdotal evidence suggests that coffee can affect the foetus. Many women note increased foetal activity if they drink coffee.

Expectant women are advised to limit both tea and coffee.

Refined packaged food sources

These are not recommended because of the refinement process which removes some, and sometimes many, of the original nutrients.

The exception is packaged frozen vegetables. Unlike supermarket produce, it is picked and ‘snap frozen’ when ripe. Research suggests that some of the desirable phytonutrients form during the ripening period. With fruit, this is in the last few days of ripening. Canned fruit can be used when fresh fruit is not available. Use the ‘no added sugar’ varieties.

Because ripening is so important, organic fruit and vegetables are desirable. They are picked closer to this ideal time before being brought to market.

'Fast' foods

‘Fast foods’ include takeaway hamburgers, pizzas, and the like. The carbohydrates of these foods are usually kilojoule-dense and nutrition-poor, and a high proportion of the fats are saturated.

In addition, the method of manufacture of these foods tends to produce trans-fatty acids. Trans-fatty acids are broken down much more slowly in your body than the recommended fatty acids, producing much larger amounts of free radicals. Some researchers have linked high amounts of trans-fatty acids to an increased susceptibility to various cardiovascular and degenerative diseases.

Fast foods also usually contain a large (often surprisingly large) amount of sugar and salt.

Margarine vs butter

Trans-fatty acids, in addition to being found in fried foods, are also found in hydrogenated vegetable oil products, in many packaged foods (check the label to be sure), and in margarine. All margarines start their life as vegetable oils—some of which are unsaturated and some of which are polyunsaturated. All are liquid at room temperature.

During manufacturing, these oils are hydrogenated (an artificial saturation process) to make them more or less solid at room temperature, and thus able to imitate the spreadability and texture of butter. This process leaves the final product full of trans-fatty acids (which, as explained above, should be minimised).

Products that are a combination of butter and margarine must be treated with caution for the same reasons.

Butter might be better, after all.

Fried food

The inadvisability of eating deep-fried food has been mentioned above, but how can you cook all of the other food that you eat?

One way is to use a variation on a traditional Chinese method of stir-frying. Instead of throwing oil into the bottom of the wok or a non-stick frying pan—and heating vigorously until it smokes, as some recipe books suggest—put in a ladleful of water or stock, instead of the oil. Depending on the recipe, you can substitute canned or fresh tomatoes. To this, add garlic and the other seasonings. Once the seasonings and other condiments have been cooked sufficiently, add the vegetables and other ingredients. Immediately cover the pan or wok with a tight-fitting lid.

Cooking this way ensures that the minimum amount of nutrients will be lost and that the food will be steamed and partially boiled.This method will ensure that the cooking temperature of the foods will not go above 100 degrees Celsius—the highest temperature that cooking water can reach.

Keeping the cooking temperature at or below 100 degrees Celsius reduces the conversion of fatty acids to trans-fatty acids. In addition, because the temperature is relatively low, some of the enzymes and other volatile food elements remain largely unchanged.

When you remove the lid and are ready to serve, you can add a good-quality oil. Olive oils and other oils can be added in this way, and the taste is different from cooking with oils. It is, in fact, delicious.

As well as the other benefits, the oil itself hasn’t been changed by the cooking process. Therefore, the benefits of the particular oil that you add will be experienced.

Most foods that are traditionally fried can be cooked in this way. Of course, you can’t make chips like this! However, chips and other fried (or roasted) vegetables should not be part of your usual diet. Keep these for special occasions!

Foods that are kilojoule-rich and nutrient-sparse (high GI foods)

The ratio of kilojoules (or Calories) to nutrients, and the GI, of any food can be changed by its method of preparation. For example, carrot juice has a much higher GI than a whole raw carrot, and is missing most of the beneficial fibre contained in a whole raw carrot. To take another example, whole grains are excellent sources of all sorts of vitamins, minerals, fibre, essential fatty acids, proteins, and carbohydrate. However, the refining process used to produce the final form of the food that most of us eat removes almost all of the nutritional components except the carbohydrate.

As mentioned previously, although white bread is often described as a good source of complex carbohydrate, it can have a GI as high as 90. Surprisingly, ordinary white table sugar has a GI of only 65, which suggests that its rate of conversion to glucose is significantly slower than white bread. (For a quick comparison, according to Brand Miller et al. 1996, cherries have a GI of only 22, apples 36, and bananas approximately 55.)

The biggest surprise in looking at GIs is that many ‘complex’ carbohydrates are treated like simple sugars by your body. Foods in the ‘desirable’ list above have lower GIs on average, and foods in the ‘less-desirable’ list have higher GIs. (Some foods in the ‘desirable’ list have relatively high GIs, but these are nutritionally dense as well.)

Don’t cut out all of the things that you really love to eat. Rather, use the lists to think about whether or not the food you are about to eat is located more at one end of the nutrition spectrum than the other, and make adjustments to suit. During pregnancy, the food that you eat feeds both you and your baby. Every nutrient advantage that you can manage is to the benefit of both of you.

Sweet carbonated drinks and refined sugar

These drinks are a perfect example of a kilojoule-dense nutrient-sparse food. The amount of refined sugar contained in sweet popular beverages is extraordinary. For example, a standard can of drink can contain 10–20 teaspoons of refined sugar. If you consume one or two cans (or bottles) of these drinks a day, you are getting a huge number of extra kilojoules that are of no nutritional benefit.

Minimise these products as far as possible. Much the same goes for the commercially made fruit juices. These also contain lots of sugar and not too many nutrients. You are much better eating a piece of fruit instead.

Some years ago, a book came onto the market with the alarming title Pure, White and Deadly. The book referred to ordinary refined white table sugar (sucrose). It now seems likely that the alleged dangers of white table sugar were exaggerated, but it is a good idea to minimise the amount of additional sugar added in cooking—simply because sugar is pure carbohydrate with no other nutrients. There might be some benefit in using unrefined sugar (rather than the refined version), but any nutritional benefits are likely to be small.

So what should you do about desserts? Desserts (like chips) are best reserved for special occasions. This is because desserts are usually relatively kilojoule-dense compared with the rest of the meal. Of course, you can calculate the approximate number of kilojoules (Calories) that you want to eat in a meal, and make the necessary adjustments. But if you are eating for two people, there are grounds for reducing the consumption of desserts and increasing the consumption of more nutritious foods.

There are, however, some desserts that are nutritious in their own right. These sorts of desserts can simply be considered as part of the total meal.

Low-fat packaged sources

Labels advertising ‘low cholesterol’ can be found on all manner of foods these days—including avocados in supermarkets and greengrocers’ shops. This preoccupation with ‘cholesterol’ is reflected in the stated goals of a US Senate Select Committee on Nutrition and Human Needs which published its report in 1977 (Grills and Bosscher 1981). These goals focus on the prevention of diet-related diseases such as obesity, cardiovascular diseases, diabetes, and dental disease. Among the goals was a recommendation to reduce overall fat consumption from approximately 40% to about 30% of energy intake (not a huge reduction) and a further recommendation to reduce cholesterol consumption to about 300 milligrams per day. Most people have absolutely no idea of what 300 milligrams a day of cholesterol means. (I certainly don’t!)

Much has been made of the association of cholesterol and other saturated fats with cardiovascular disease, and this is one of the reasons for fat-free and low-fat foods being promoted so aggressively. The problem with this recommendation is that it makes no distinction between beneficial and harmful fats. A further problem with very low-fat products is that the remainder of their composition is largely carbohydrate. Above, we noted that if complex carbohydrate is eaten without the GI-lowering effects of the right kind of fat and fibre, the conversion of complex carbohydrate to glucose can be very rapid.

Another associated problem is that in the effort to make the processed food as low in fat as possible while retaining the ‘taste’ of fats, the use of various substances not found in the original food has increased. For example, commercially prepared yoghurt contains all sorts of chemicals that are not in the original milk (soy, dairy, or goat’s milk) that is used to make traditional yoghurt. Minimising the intake of these additional substances is probably prudent.

Artificial sweeteners should also be regarded with caution. Sears (1999, page 281) states that aspartame ‘should never have become part of the food supply’. Use natural sweeteners sensibly.

'Convenience foods'

Many of the remarks made about other foods also apply to convenience foods. The only real ‘convenience’ here is preparation time. If one is eating with nutrition in mind, the ‘convenience’ might turn out to be an illusion.

The basis of the sensible eating plan

The following section provides more detail on certain elements of nutrition. You might feel that you already have enough information on which to base your eating plan. However, if you feel that more detail will assist your food choices, read on!

Fifty nutrients are essential to support human life. They are discussed below.

Essential amino acids

There are twenty-two amino acids, but only nine (or eleven for premature infants) are ‘essential’ in your diet. If your body has the full spectrum of these essential amino acids your body can make the remainder.

All animal sources of protein are ‘complete’—meaning that all the essential amino acids are present in a ratio that is favourable for humans. However, all animal protein sources contain saturated fat as well.

Vegetarian sources vary in the favourability of their ratios. For example, corn has been traditionally eaten with beans in some parts of the world. Corn on its own lacks an amino acid called lycine, but beans have this amino acid in abundance. Together, corn and beans contain all the essential amino acids in a favourable ratio.

Recent research suggests that your body has an amino acid ‘pool’—which exists for half a day to a number of days. If you are a vegetarian and you eat a protein source that is low in a particular amino acid, you probably don’t have to worry too much. At the next meal you will probably eat a food containing the missing amino acid. However, if you wish to be meticulous, and you think that there is a benefit from eating complete proteins at every meal, give some thought to combining your proteins.

Another traditional protein combination is rice and sesame seeds. There are several other similar combinations. Diet for a Small Planet, an excellent source of nutritional advice, is an invaluable source of this kind of information. Note that all the grain sources have some high-quality protein, and this content is higher if the grain source is unrefined (unprocessed).

Essential fatty acids

There are only two essential fatty acids. If you have the two essential fatty acids in your diet in the right proportion, your body can make all of the other fatty acids needed for health.

The opinions of researchers differ considerably on the ideal proportion of omega 3 to omega 6 fatty acids. Erasmus (Fats that Heal, Fats that Kill) suggests that most people in the modern Western world are significantly deficient in LNA, an omega 3 fatty acid. If your diet in the past has been high in saturated fats and you have eaten a lot of fried foods (and hence have had significant amounts of trans-fatty acids in your body), Erasmus recommends adding extra omega 3 fatty acids to your daily intake for six months or so.

The best vegetable source of this particular fatty acid is the oil derived from flax seeds. This is available in the refrigerated section of health food shops. This is a particularly reactive substance, and for this reason it is sold in opaque containers, and must be kept refrigerated. Never use this for cooking. It is best added to foods after cooking, or on top of other breakfast cereals or yoghurt. A tablespoon or two is the recommended daily amount. Once you feel that you have achieved some sort of balance in the fatty acids in your body, you might wish to change the proportion of the two essential fatty acids.

Apparently hemp oil contains a more or less ideal balance for human consumption—but I haven’t seen any hemp oil available in my local health food shop! A better way is to combine flax-seed oil with one of the other cold-pressed vegetable oils that is rich in omega 6 fatty acids. These include safflower oil, sunflower oil, and sesame-seed oil. Again, do not use these oils for cooking—they are damaged by heat. They should be mixed up and used as a salad dressing, or used as a topping on other foods.

The main fatty acid of olive oil is oleic acid. This is not an essential fatty acid, but it might have benefits for people at risk of cardiovascular disease—provided it is virgin or extra virgin olive oil. These terms refer to the pressing process that removes the oil from the olives, and virgin or extra virgin olive oil are produced in a way that maintains the maximum nutritive value of the oil. The term ‘light’ (and other terms that you see on oil labels) tells you that it is not virgin—and hence processed in some way. Such oils should be minimised or avoided.

Minerals

In Australia, until recently, vitamin and mineral preparations were not permitted to contain selenium—even though Australian soils are said to be the poorest in selenium of any soils in the world. The reason for this prohibition was that, like many substances, selenium is toxic in large doses. However, selenium is now a permitted mineral in supplements.

The results of a full blood assay can be very helpful in planning food choices and possible mineral supplementation. This test is available on Medicare if recommended by a doctor, so you might wish to discuss this with your medical practitioner.

Of particular interest to expectant women are three minerals—iron, calcium, and magnesium.

Anaemia (low haemoglobin level) is caused by insufficient available iron. Sometimes women can feel tired and be told that their haemoglobin levels are ‘within normal limits’. Despite this apparent ‘normality’, many women find that iron supplements can help, and can increase their energy significantly. A daily supplement of one tablet per day (each containing about 100 milligrams of elemental iron) is recommended. These are available ‘over the counter’ at pharmacies.

You might prefer to address this problem through diet rather than supplements. Constipation can be a side-effect of iron tablets, if there is insufficient fibre in your diet. Everyone Jennifer talked to about this problem, including midwives, believes constipation is a problem regardless of dietary fibre intake. Consider a couple of teaspoons of Psyllium husks with all meals if this is the case for you. Dark-green leafy vegetables are an excellent source of dietary iron.

Calcium and magnesium are required for healthy bones—both in yourself and your baby. The recommended daily allowance of calcium is 800–1200 milligrams per day, and the recommended allowance for magnesium is 300–400 milligrams per day. Some recent US research suggests that magnesium is also an important mineral in avoiding or reducing the likelihood of cardiovascular problems. To be on the safe side, it is probably a good idea to have a daily mineral and vitamin supplement obtained from some reputable source. (Floridix is a preparation that Jennifer used.)

The best supplements contain different forms of the various minerals, some of these being described as ‘chelated’. This means that the element is coated, or prepared with a particular amino acid, so that the substance in question can be better assimilated by your body. If you are concerned about any possible effects that such a supplement might have, discuss it with your doctor.

Vitamins

There are thirteen recognised vitamins. No new vitamins have been named since 1954, even though thousands of phytonutrients (compounds contained in plants) have been discovered since then. The term ‘vitamin’, and how it can be applied to particular substances, is subject to two strict criteria. The first is that the absence of the substance in the diet must be causally linked to a particular disease. The second is that the addition of that substance to the diet must be able to reverse the course of the disease. For example, the absence of vitamin C causes scurvy, and the reintroduction of the vitamin reverses the disease process.

However, these criteria have proven to be too restrictive in terms of adding to the list of vitamins. Some researchers feel that many phytonutrients (not classed as vitamins) have important health-giving properties—even if they are not essential. Certain phytonutrients are likely to be extremely important in helping your body deal with cancer cells that are produced every day. For example, the brassica family (including cauliflower, Brussels sprouts, and broccoli) is said to contain a number of phytonutrients that are beneficial in halting the course of some cancers. This is another good reason to get a significant fraction of your day’s carbohydrates from a variety of vegetables—because they each contain different phytonutrients in various proportions.

Some of the vitamins are called ‘antioxidants’. These include vitamins A, C, and E. If you are going to supplement vitamin A intake, it is better to take beta-carotene (a double molecule of vitamin A that your body breaks down as needed), or to make sure that you eat as many different coloured vegetables as possible. The antioxidants combine with substances called ‘free radicals’—which are produced in all oxidative reactions in the body (such as those required to metabolise trans-fatty acids). Some researchers claim that excess free radicals in your body can damage your chromosomes, and hence compromise your body’s ability to reproduce its cells accurately. This might be a significant part of the ageing process. Most of the cells in your body are renewed within a brief two-year period—that is, at the end of a two-period you are actually composed of different molecules. In this sense, ‘we are what we eat’—because our bodies can be ‘remade’ only from the things that we take in each day.

Among the B group of vitamins is folic acid (vitamin B9). This vitamin is essential to the developing foetus. Below, you will find a chart reproduced from a recent source showing which ordinary foods contain folate, and in what amounts.

The recommended daily allowance of cobalmin (vitamin B12) is extremely small (0.006 milligram per day). However, it is a crucial nutrient, and vegetarians should know that strict vegans are likely to have low B12 stores. If you suspect that you might be low in vitamin B12, it is worth getting a vitamin and mineral supplement that has adequate amounts of this vitamin.

Vitamin D is manufactured by the body and its manufacture is accelerated by exposure to ordinary sunlight.

Be aware of the interaction between vitamins and minerals on the one hand, and the macronutrients (protein, carbohydrate, and fat) on the other. As mentioned, all the minerals and vitamins are necessary for the effective metabolism of the macronutrients.

Foods containing folate

Folate helps to prevent neural tube (spinal cord) abnormalities in the foetus. These abnormalities include spina bifida. Folate might also be important in preventing miscarriage in the early stages of pregnancy.

The recommended daily allowance (RDA) for folate is 400 micrograms. This should be taken by all women who might become pregnant because it is important to have adequate folate at the very beginning of pregnancy (indeed, before women know that they are pregnant), as well as during confirmed pregnancy. Women who have a history of giving birth to babies with neural tube disorders should take as much as 4 milligrams per day.

Adequate folate must therefore be consumed, and most women should probably take supplements in addition to being aware of the following dietary sources. If you have any queries about this important matter, consult your medical practitioner.

Folate and food sources (pdf, 204kb)

Energy sources

There are no essential carbohydrates in the way that there are essential amino acids and essential fatty acids. However, everyone needs good sources of energy.

The best sources of carbohydrates are wholegrain products, fruits, and vegetables. Commonly, food pyramids separate these foods, giving the impression that the carbohydrates that they contain are somehow fundamentally different—but they are not. Most of the food pyramids have grain sources at the bottom, and recommend that they should form the major fraction of your carbohydrate intake. If the food from these grain sources is largely unrefined, this is good advice. Such food is full of minerals, vitamins, good-quality protein, beneficial fatty acids, and carbohydrate. However, in the refining process, much of the good nutrients are lost and you are left with relatively nutrient-poor carbohydrate.

All vegetables and fruits are excellent sources of carbohydrate and are comparatively rich in nutrients. It is therefore advisable to use these for your carbohydrates—rather than emphasising the grain-based sources.

Another consideration is the glycaemic index of a food source. In one sense, the concept of a glycaemic index is deceptive. For example, if you combine a high GI food with a low GI one (depending on the precise nature of the foods involved), the glycaemic index of the whole meal will be a figure between the index of each food. It is desirable to get a balance of high and low glycaemic foods in the same meal, to avoid excessive increases in blood sugar following eating.

A further dimension to consider in assessing energy sources is the amount and kind of fat and fibre present in the same meal. Both of these decrease the overall glycaemic index of the meal.

Finally, individual reactions to particular foods will vary the GIs by very significant amounts. A variation of 20% or more can be seen in the figures cited (see Brand Miller et al. 1996, pages 207–40).

Oxygen

This element is an obvious necessity. No one can survive more than a few minutes without oxygen. Make sure that you have enough fresh air blowing through your house during the day. If you work in an office, it is essential to get out of the office environment at some time—perhaps at lunchtime—and expose yourself to cleaner air (it is to be hoped that it is cleaner!) than you find inside a typical office. Walking at any time of the day that you can manage it is good too.

Light

The action of light on the skin helps your body create the essential vitamin D. The action of light on the retina also stimulates the pineal gland and helps some people to avoid the unpleasantness of seasonal mood disorder—sometimes called ‘seasonal affective disorder’ (SAD).

Water

Recommendations for how much water one should consume daily vary quite widely. It depends on your body weight, level of activity, and so on. However, a minimum recommendation for water consumption is two litres per day.

If you are concerned about your water intake, substitute a glass of water for the cup of coffee or cup of tea that you might otherwise have.

Because water forms approximately 70% of your body weight, it is wise to give some thought to the purity of the water you drink. Benchtop water purifiers can be helpful, or drink best-quality bottled water. Read the label on bottled water to determine the source—the information might surprise you. Tap water in Australia is usually safe to drink. Another way to increase your fluid intake is to have nutritious soups at mealtimes. If you like fruit juices, but are concerned about getting too many kilojoules, dilute the juice by half with water.

Movement

In a book concerned with stretching and strengthening exercises, the recommendation for movement might seem superfluous. However, it is an essential consideration on a daily basis and, when taken together with the need for oxygen and light, provides a good reason for getting out of the house or out of the office at least once a day, and going for a walk.

Every authority considers walking to be excellent exercise—provided that walking doesn’t give you neck or back pain, or aggravate some pre-existing condition. If this is the case, swimming can be substituted for walking. Going for a walk gives you a chance to open your lungs fully, to breathe deeply, and to make sure that you get enough direct sunlight (to stimulate your brain and help your body make vitamin D).

Walking is also fun! Of course, if the conditions are too hot or too bright, make sure that you go out with a hat on and cover your skin. The last thing you want is a case of sunburn while pursuing your health goals.

Breastfeeding

Breastfeeding is desirable. Apart from the health benefits—the full extent of which have become obvious only in the last ten years or so—women tend to return to their previous weight much more quickly if they breastfeed. One reason for this might simply be the huge energy requirement of lactation.

Maureen Minchin (Breast Feeding Matters) identified what she called the ‘six o’clock starvation syndrome’. This can be attributed to the energy cost of lactation. Breastfeeding mothers should eat as many nutritious snacks as you feel you need. The reasons for this are obvious—not only do you need to run around and do the normal things that people do in their daily lives, but also you need to have enough energy to produce sufficient milk for your new baby. When you are breastfeeding, you will need to give additional regard to what you eat. In Jennifer’s case, for example, eating chick-peas had an undesirable effect on her daughter immediately following breastfeeding.

 

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