Real Food for Pregnancy: The Science and Wisdom of Optimal Prenatal Nutrition

“Maternal nutrition plays a critical role in fetal growth and development.”
– Dr. Guoyao Wu, Texas A&M University

T he message that a mother’s nutrient intake during pregnancy affects the development of her baby is well accepted across multiple nutrition philosophies and among traditional cultures. Even if this is the first nutrition book you’ve ever picked up, I’m sure you agree as well.

You might be wondering why I bothered to write a book about prenatal nutrition if everyone agrees on this basic principle. Well, outside of a few select nutrients, there’s actually more disagreement than there is consensus on this subject. Digging into the details of conventional prenatal nutrition guidelines—and comparing them to both scientific research and the wisdom from ancestral diets of traditional cultures—uncovers many discrepancies, which is why I’ve written this book.

Before I go any further, allow me to define a few terms that I will reference frequently. Conventional nutrition refers to dietary advice based on the U.S. government’s nutrition policies. These dietary guidelines formed the basis of the notorious food pyramid. Although the food pyramid was officially replaced with a plate, the overall message has remained virtually unchanged for decades: eat less meat, limit saturated fat, and eat more grains. Ancestral diets and those of traditional cultures refer to the dietary practices of people who lived several hundred years ago and beyond (although there are still some isolated populations that live this way). Since this was before the advent of mass-produced food and industrialization, the focus was on real food, obtained locally and eaten in its natural, unprocessed form. I will use the terms ancestral diets, ancestral nutrition, foods from traditional cultures, and real food interchangeably.

Although both conventional nutrition and traditional cultures have their similarities—for one, they generally tend to emphasize the importance of fresh produce—they most certainly have their differences. Conventional prenatal guidelines discourage the consumption of fatty meat and organ meats, suggest limiting seafood intake (no more than 12 oz per week, they say), direct you to choose only low-fat dairy products, and contend that you need a high intake of carbohydrates (45-65% of calories) to ensure the health of your baby.

In stark contrast, traditional cultures consumed animals “nose-to-tail,” prized the fattiest cuts of meat, went out of their way to obtain seafood (even in landlocked areas), never skimmed the fat off of their milk (if they were a milk-drinking community in the first place), and did not consume anywhere near the level of carbohydrates currently recommended. Plus, refined carbohydrates—like white flour and white sugar—didn’t even exist until the last century or two. Conventional prenatal nutrition guidelines only specify making “half of your grains whole.” Flip that around and what they’re essentially saying is that it’s perfectly acceptable to eat half of your grains in the form of refined cereal and white bread.

So who’s right: conventional nutrition or traditional cultures? As I started to meticulously pick apart the scientific literature, I came to surprising, and rather disappointing, conclusions. As a dietitian, I would expect better from our public policies.

In short, current research finds that the nutrients most commonly lacking in a prenatal diet—like vitamins A, B12, B6, zinc, iron, DHA, iodine and choline—are found in the very foods you’re told to limit by conventional prenatal nutrition guidelines. Plus, the more carbohydrates you eat—especially refined carbohydrates—the fewer micronutrients your diet contains (meaning vitamins and minerals), and the higher your chances of developing pregnancy complications.

Though some may shrug their shoulders and think “Well, that’s why a prenatal vitamin is recommended,” I’m sorry to say that most prenatal vitamins contain nowhere near the levels of nutrients required to ensure a healthy pregnancy and many lack key nutrients entirely (such as iodine and choline). In addition, some prenatals contain poorly utilized forms of nutrients (like folic acid instead of L-methylfolate). A high-quality prenatal vitamin can serve as an insurance policy of sorts, but there really is no replacement for a nutrient-dense diet of real food.

Although I’ve always had an interest in prenatal nutrition, I didn’t come to fully appreciate its importance until I witnessed the effects of suboptimal nutrition on pregnancy outcomes firsthand. It was working both clinically and at the public policy level on gestational diabetes, the type of diabetes that either first develops or is first recognized during pregnancy, that really piqued my interest. Upwards of 18% of pregnant women face this diagnosis, and when not well managed, it can leave a lasting impact on their children’s health. In fact, babies born to women with gestational diabetes face a 6-fold higher risk of developing type 2 diabetes by the time they are 13 years old.[1] Between 2001 and 2009, there was a more than 30% increase in the prevalence of type 2 diabetes among children, and the rates are only projected to increase.[2] These statistics are frightening and highlight just how important a mother’s nutrition and blood sugar levels are to her baby. The epidemic of childhood diabetes and obesity we’re currently witnessing is not only due to poor food choices or inactivity during childhood, but also to inadequate nutrition and metabolic problems they have been exposed to in utero.

The striking difference between conventional prenatal nutrition and a real food or ancestral approach was made especially clear in my clinical gestational diabetes work. It was in this role that I was able to put conventional nutrition advice to the test alongside my “real food approach” and see how it impacted both blood sugar levels and pregnancy outcomes.

The results were nothing short of astounding. Using my real food approach, we were able to cut in half the number of women who required insulin or medication to manage their blood sugar. We also had excellent outcomes: healthier moms who didn’t struggle with hunger or excessive weight gain; who had far lower rates of preeclampsia; and who had healthy babies who were born at a normal weight and with normal blood sugar levels. It was amazing to witness the impact that real food had on pregnancy outcomes. It wasn’t effective just because my approach was lower in carbohydrates, but because it contained exponentially higher levels of nutrients than the conventional gestational diabetes diet.

I was encouraged to write my first book, Real Food for Gestational Diabetes, to get the message out to other moms, dietitians, and healthcare providers, and within a few months, it became (and remains, at the time of writing this) the bestselling gestational diabetes book on the market. I’m heartened to regularly receive messages from mothers, even those who have had gestational diabetes in previous pregnancies, who share stories of their smooth pregnancies and healthy babies as a result of their efforts in following my approach.

I started getting asked to write a book on general prenatal nutrition shortly after the release of my first book. Midwives and doctors who had seen the positive impact on gestational diabetes wanted to have a resource for their non-diabetic clients. They also wanted my take (or really, a summary of the research) on other topics related to pregnancy, like supplements, exposure to toxins, the validity of typical “foods to avoid” lists and more.

Initially, I resisted, figuring there were already plenty of books on the market on this topic. But, I’ve come to find there really aren’t—at least none with the level of evidence-based information that we so desperately need in order to finally shift the most outdated prenatal nutrition advice. Most of what I’ve come across either shares conventional guidelines or offers their personal opinion, without citing sources for their information, nor studies to back their claims.

The last straw was when a colleague came to me with several questions about prenatal nutrition based on what she had read in the Academy of Nutrition and Dietetics’ policy paper on pregnancy nutrition entitled “Nutrition and Lifestyle for a Healthy Pregnancy Outcome.” In case you’re not familiar, the Academy of Nutrition and Dietetics (formerly known as the American Dietetics Association) is the professional organization that governs the practice of registered dietitians and influences nutrition public policies in the United States. My jaw nearly dropped to the floor as I read through this policy paper. While I didn’t disagree with everything, there were some obvious oversights and it was clear that now was time for me to write this book.

Among the most disappointing things in this document was the sample meal plan. It was the epitome of prenatal nutrition gone wrong. Breakfast was nearly devoid of protein and fat (only oatmeal, strawberries and low-fat milk). The quantity of carbohydrates was through the roof (over 300 grams). And there was absolutely nothing satisfying about the afternoon snack of crackers and carrots. There was no red meat, no eggs (unless you count the tiny amount in low-fat mayonnaise), and certainly no organ meats. Just about the only thing I was relieved to see was salmon served at dinner, though it was accompanied by plain steamed broccoli, white rice, and more low-fat milk (and there was no mention of the importance of choosing wild-caught vs. farm-raised salmon). This was the polar opposite of a sample meal plan I might share with a client. I was hungry just reading it.

I couldn’t fathom, given all that I know about the food sources of tricky nutrients, like choline and vitamin A, how this diet could ever meet a pregnant woman’s needs. I decided to compare a nutrient analysis of their sample meal plan to one of my own.

The results confirmed my suspicions. Each meal plan had equivalent calories, but the nutrient-density was a different story. Of the micronutrients I analyzed, my meal plan came out on top for 19 of them. Specifically, my meal plan had approximately triple the quantities of vitamin B12, double the quantities of vitamins A and E, 55% more zinc, 37% more iron, and nearly 70% more choline. It was also higher in brain-boosting omega-3 fats and had a more favorable ratio of omega-3 to omega-6 fats. It was particularly worrying to see that the Academy of Nutrition and Dietetics’ meal plan had very little preformed vitamin A, known as retinol, since animal fats were extremely limited.

Needless to say, I respectfully disagree with the conventional prenatal nutrition guidelines and I cannot, in good conscience, recommend their sample meal plan to pregnant women. Depriving a mother’s growing baby of key nutrients needed for things like brain development goes against the “first, do no harm” principle that’s central to ethical medical care across the globe. It often takes decades for research to make it into practice—and for old policies to be significantly reformed—so it’s not surprising that we have found ourselves in this situation. But, we can do better.