Pregnancy. What comes immediately to mind is always food-related – nausea, cravings, vomiting… True, I didn’t suffer from any of these symptoms myself, but during my wife’s pregnancies I was the one who worked hard. Like any real man, I tried to supply my wife with the best nutrition for her and for our developing fetus, and yes, I also did my best to give her as little help as possible while she was trying to remember where on earth did she last see the little orange jar of dietary supplements.

A large and diverse body of knowledge about nutrition during pregnancy exists today, and the common opinion, even in “conventional” academic circles, is that better maternal nutrition increases the chances of a successful birth and lowers prenatal mortality. Despite this, pregnancy is not usually treated as an event that demands a nutritional overhaul, but rather as a state that requires nutritional supplementation only. As I do for other nutritional issues, I would like to offer a historical-anthropological view that leads to a radically different approach to nutrition during pregnancy.


Already in the 1930’s, the researcher Weston Price warned of scorning those traditions still in place in native societies which connected maternal diet during the pregnancy to the child’s health. During his research Price discovered that in every culture he observed there were foods that were reserved for pregnant women, and sometimes also for those likely to become pregnant . These foods were usually the most nutritious ones available at that area during that season, and usually full of valuable proteins, fats, vitamins and minerals, and low in carbohydrates.

For example, in certain pacific islands tribes, when a woman became pregnant, the chief would hold a ceremony in which he would appoint two young men whose task it was to provide her with unique sea foods; In the Fiji islands pregnant women were fed a certain type of spider crab, which was believed to produce children “physically excellent and bright mentally”; The Eskimos as well as native people living on the coast of, provided pregnant women and adolescent girls with fish eggs; In Africa certain water plants were collected and burned, and their ashes sprinkled on top pregnant women’s food; In Switzerland and other places, high quality dairy products were eaten, produced during the season when the grazing grounds were richest.

Pregnancy in an evolutionary perspective

It seems that our evolutionary history offers profound implications for our nutrition in general, and for nutrition during pregnancy in particular. Researcher Andrew Prentice formulated a theory he calls the Thrifty Gene Theory, explaining our body’s tendency to store sugars as fat deposits (i.e., to put on weight). It seems likely that humans have lived for 99% of their evolutionary history in societies where food was not readily available throughout the year. Times of hunger created a clear preference for the survival of those people whose bodies stored extra fats during times of plenty. If we look back in evolution only to the point where we branched off from our closest living relatives, we are looking at about 250 thousand generations of evolution through natural selection. It means that we are genetically programmed to put on weight, because whoever didn’t, didn’t survive lean times. Various researchers use this theory to explain the obesity and diabetes problems plaguing industrialized societies.

But during the pregnancy you put on weight because there’s a baby, and there are hormonal changes, and…

So what does all this have to do with pregnancy?

Surviving offsprings consider “children” or “progeny” instead of offsprings pass on the genes of the parents who succeeded in carried them to term and delivery. Their success is actually measured in their ability to produce another set of fertile offsprings (or children), and thus in the production of grandchildren. Surprisingly, the chance that a conception will produce grandchildren is only 7 in 10,000. The pregnancy, the ability to birth successfully, and the ability of the baby to survive are all significant factors in our evolutionary history.

There are two important factors for a fetus’s survival during times of hunger:

1. The ability of the mother to conserve energy for her fetus, ensuring it will be born at a size that enables its survival. This is done using a metabolic trick that will be described below, during the discussion on gestational diabetes.

2. The ability of the baby to take energy from the mother even if she is malnourished, without hurting her ability to lactate when the baby is born.

The factors assisting in turning a conception into a healthy pregnancy during times of hunger are those that provide the mother with a genetic advantage over women who don’t have this mechanism. Thus, the fetuses that survive are those whose genes help them to obtain the primary function of evolution during pregnancy – fattening the baby so it can live, and fattening its mother so she can carry and feed it.

Researcher James Neel ties the thrifty gene theory to the development of gestational diabetes and to the fact that it produces exceptionally large babies. Gestational diabetes is a pathological condition occurring when the mother isn’t sensitive enough to the sugars coming into the blood stream and doesn’t secrete enough insulin that directs the sugars to the cells. As a result, the sugar levels in her blood rise and thus reach the fetus directly and nourish it. Gestational diabetes affects one to three percent of pregnant women, and is especially prevalent among women from low socio-economic background, obese women, and in the Middle East and Asia, in societies whose diet is rich in refined carbohydrates and in societies that made a sharp and recent change to a Western diet.

According to Neel’s approach, gestational diabetes can be viewed as a maternal mechanism that directs some of the sugars in her food to the baby. The factors affecting this mechanism are the ability of the mother to use fewer sugars for herself and the ability of the fetus to take the excess of sugars for itself. Neel believes these parameters have an evolutionary origin. If we look back in time we might be able to reconstruct a scenario where gestational diabetes was a mechanism that enabled women to carry pregnancies and give birth during times of hunger – the mother secreted less insulin and the fetus could extract nourishment from sugars in the blood stream. Because these are mechanisms adapted to a state of hunger, a problem arises when they meet a nutritional reality of sugar surplus arising from a diet rich in carbohydrates, to which they are not adapted. In this case, the metabolic process could become unbalanced and cause the pathological condition of gestational diabetes. Research is still not clear on the question of whether insulin secretion changes during the pregnancy of women who are not diagnosed as suffering from gestational diabetes, so every pregnant woman would be wise to eat as though she were at risk for gestational diabetes.

The thrifty gene theory stresses the evolutionary origin of common nutritional problems, but it isn’t without its problems, and as is the case with most evolutionary explanations, it cannot give a full explanation for all the observable phenomena.

As mentioned earlier, our bodies are built to survive and pass on our genes especially in times of hunger. Because the pregnancy is a major bottleneck in times of hunger, the physiology of pregnancy is evolutionarily suited for times of hunger and not for times of plenty. But because we live in times of plenty, it’s very important to pay attention to our nutrition. I do not advocate starving pregnant women, of course, but I also believe we should not encourage limitless gorging. Most importantly, we need to understand the individual needs of every woman and tailor her nutrition to her specific situation (notice that this article does not consist of individual dietary counseling, but rather contains general observations!).

The role of nutrition during pregnancy

Both the written history of nutrition during pregnancy and folk traditions from around the world can supply us with a framework to help us understand nutritional needs during pregnancy. Combining historical and traditional knowledge with modern knowledge about the physiology of pregnancy, and with local and nutritional conditions, enables synthesis and the creation of a new conceptual framework. It’s important to stress that no two pregnancies are alike, and that nutritional recommendations should be individually tailored to specific circumstances. For this reason, this article tries to construct a general frame of reference for understanding pregnant women’s nutritional needs and enabling the treatment of pregnant women using nutrition, from a general point of view.

As we have seen in the first part of the article, the amount of food consumed during the pregnancy isn’t necessarily the central nutritional change. The types and quality of foods eaten are essential, especially in our society where the amount of food is often given more importance than its quality (a problem unsuccessfully addressed by using dietary supplements). The central nutritional goal during the pregnancy, according to current scientific research, is optimizing the body’s ability to absorb those nutrients necessary for a healthy pregnancy. A decrease in the levels of minerals and vitamins during the pregnancy is to be expected, although it seems to point to a problem according to standards appropriate to non-pregnant people, and is thus alarming to the medical establishment. But pregnancy is a physiologically unusual state, and should be measured by different standards.

It is difficult to withstand the barrage of general recommendations for dietary supplementation issued by the medical community. During my wife Tali’s first pregnancy, we too were gripped by fear of an unhealthy pregnancy and hurried to purchase dietary supplements. At a routine checkup at the nurse’s office, where we discussed the results of one of the blood tests (which were perfectly standard for pregnancy), the nurse insisted that Tali suffers from iron deficiency. She instructed Tali to take at least four iron supplements a day, stressing that even that is a low amount relative to what is needed for a successful birth. Tali even took folic acid with her iron supplements for a short while, but after evaluating her nutrition and much discussion between us, she stopped.

In Israel, Iron is perhaps the most common dietary supplement taken during pregnancy, because of the decrease in iron values in the blood. It’s routinely prescribed even though it is widely known that iron values in the blood normally decrease during pregnancy, and indeed they have to because of the increase in blood volume, despite the fact that a woman with good dietary habits only needs supplementation in case of a pathological problem. The problem is that defensive medicine steadily raises the bar for what’s considered a pathological decrease in iron levels in the blood, and today almost all women receive a recommendation for iron supplementation. This is no small thing, because synthetic iron supplements given to a healthy woman can cause an opposite reaction – in the second half of the pregnancy iron absorption efficiency rises dramatically as part of the body’s effective mechanism regulating vitamin and mineral absorption through the digestive system (absorption efficiency is measured via the percentage of iron absorbed through food. The higher the percentage, the better the absorption).

The rise in absorption efficiency occurs only among women who don’t take dietary supplements. When a woman takes a synthetic iron supplement, she receives an amount of iron many times greater than she would receive through diet alone. This woman will indeed continue to absorb into her blood the same percentage of iron as she did earlier (because the efficiency of her absorption didn’t rise), but she will do so out of a much greater amount of iron present in the pills she takes. Thus among those women who supplement with iron, iron levels can rise too high, both in the digestive system and in the blood. Symptoms of excess iron in the digestive system are well known, including constipation, diarrhea, headaches and more. Symptoms of excess iron in the blood are less obvious, but it is known that absorption of vitamins and minerals is co-dependent, and an excess of one mineral can impede absorption of other minerals and vitamins.

A bit of history

People in antiquity were concerned with much of the same problems surrounding pregnancy as we are today, such as avoiding congenital defects, various cravings, nausea, excessive appetite or lack of it, etc. These problems were mainly treated by nutritional changes.

Among those, cravings are probably the most common, and best researched, phenomenon. A craving for clay is known among South American and African women, although this isn’t the most common craving; the widest known cravings are for fruit. I would venture a guess that the origin of these cravings is our mostly fruit-based diet as hunter-gatherers. A craving to consume non-food substances (like clay) is called pica, and attributed by many researchers to nutritional deficiencies.

For Muslim doctors in the Arab Empire of the Middle Ages, nutrition was a central tool in treating pregnant women. These doctors were influenced by ancient Greek and Ayurvedic (Indian) medicine. The central, recurring recommendation in their writings is: Don’t eat too much, don’t eat too little, and eat many small meals throughout the day. There are also more specific recommendations, embedded in contemporary dietary customs. Among foods that were not to be indulged in, we find wine, pork, fish, salt, capers, unripe olives, green beans, chickpeas, and celery. Very sour, bitter, and sweet foods were to be avoided. Some of the recommended foods include: Poultry, young goat (prepared in wild grape vinegar), small amounts of diluted wine (recommended also for the breastfeeding period), onion, mustard, quince, pomegranate, sour apples, lime, and soft eggs. To combat vomiting and gluttony the ancient doctors recommended food that was not too bitter or too sweet, light white wine (aged five years), walking, and drinking slowly. To combat heartburn they suggested taking small sips of hot water, long walks, and placing soft fleece on the stomach. Against nausea – eating spiced foods and dry starches. Large women suffering from nausea were to eat spicy foods, and especially mustard.

To combat pica (the craving of non-food substances) the doctors recommended small amounts of old and slightly sour wine. They further advised eating before a meal any of the following: Pickled olives with soft bread, a few bitter almonds, barley meal in pomegranate juice, chicory, lettuce, lean poultry, pig snouts, stomach, and feet, and fresh fish. Following a meal, it was thought helpful to eat raisins, pomegranates, and pears. If the suffering from pica was great, it was recommended to eat pickled fish, radishes in honey and vinegar, pomegranate juice, and nutmeg. Women craving clay were advised to try cooked beans with sugar instead.

The ancient doctors also recommended bathing often during the 9th month of pregnancy.


In our contemporary society, pregnant women are encouraged to eat any food they desire, with no restrictions, and to treat the resulting deficiencies with dietary supplements. This common approach causes problems in the amounts of food consumed by pregnant women, and in its quality (especially regarding sugars).

As we’ve seen, the situation in antiquity was in stark contrast. Women received the best food available before and during pregnancy, natural food that supplied them with vitamins, minerals, and proteins of the highest quality. Today, pregnant women eat chocolate (enough for two, of course) and take iron supplements.

The wise traditions and anthropological data sketch a different conceptual framework from the one we are accustomed to, built on two basic guiding principles:

1. Quality – women should receive food of the highest quality all through their reproductive phase, and especially during pregnancy and breastfeeding. (No, Belgian chocolate with 70% cocoa solids isn’t considered to be of high enough quality in this regard. Organically raised poultry is).

2. Moderation – it’s important not to eat too much or too little. In practice, a woman accustomed to a high quality diet before the pregnancy will be able to balance her intake herself, following her sensations of hunger and satiation.

This conceptual framework can assist women who are pregnant or trying to conceive, and who are interested in eating in a way that will support a healthy and successful pregnancy. But the information offered here is mainly important in creating the framework, and the reader should hold in mind that coloring in the details is no less important. Coloring in the details would be, in this case, the decisions what to eat, how and how much. These decisions should be tailored to each individual woman and to her specific medical situation, and they should vary amongst women.

It is also important to note that nutrition is only one facet of behavior during pregnancy, and that other facets are no less important, such as physical activity, lifestyle, and emotional state.