How many carbs should I eat now that I’m pregnant?
A healthy Paleo or Primal diet is naturally lower in carbohydrates when compared to the standard American diet (SAD) and commonly ranges from 10-35% depending on individuals’ needs, goals and preferences. Your carbohydrate needs in pregnancy may need to be altered from its non -pregnant levels, both as your activity levels modify and as your body works hard to grow a new life. In this post, I’ll answer the not so simple question to, “How many carbs do I need when I’m pregnant?”
If you are overweight and/or have a diagnosis of PCOS before becoming pregnant, your risk of pregnancy related complications may be diminished by reducing your weight to ‘normal’ levels and learning to control your insulin levels with Paleo eating and exercise. A common weight reduction strategy among Paleo eaters is to adopt a low carb or very low carb (VLC) approach. Reducing carbs when overweight or struggling with metabolic syndrome can be an incredibly effective tool for fat loss and insulin control, however when pregnant, this approach can cause some issues and it’s important not to attempt weight loss when pregnant in order to properly nourish your growing baby.
Pregnancy is a natural anabolic (growing) state; the object of the game here is to grow a new life! The body facilitates growth in pregnancy by creating a natural state of insulin resistance thanks to a variety of hormones including a hormone produced by the placenta called Human Placental Lactogen (HPL). To simplify, your blood sugars are naturally higher when pregnant in order to facilitate adequate glucose transfer to your baby. Remember high school chemistry? Sugars move from high concentration (your bloodstream) to low (baby’s blood stream) through the process of simple diffusion as they cross the placenta. This balance helps your baby grow and also helps you put on stores of fat especially in the first trimester, ensuring adequate calorie stores for breastfeeding.
If you are eating a low carb or very low carb diet, you may be producing ketone bodies. Ketones are the waste products of fatty acid metabolism, aka when the body burns some of its own fat for fuel. Normally ketones pass from the bloodstream into the urine and are excreted. Your body also will adapt normally glucose driving functions such as brain activity, utilizing ketones for fuel. Everyone’s body begins to producing ketones when carbohydrates become scarce. While for some, eating less than 50g/day of carbs may create ketones, others don’t produce them unless they are eating 20g/ or less. In essence, everyone is different and a simple at home urine test with a ketostick will help you determine if you are excreting ketones.
Ketones during pregnancy can cross the placenta and can affect your babies’ development. Some studies have shown that excess ketones in a pregnant woman's urine may affect developing brain cells and lead to babies with a lower IQ and create future learning disabilities. Other studies suggested that ketones and low brain glucose levels in developing fetal brains may also interfere with serotonin receptor development, which may be associated with mood related disorders later in life. If your blood sugars are consistently too low and/or you are in a state of ketosis from a low carbohydrate diet, it puts adequate glucose transfer to your developing baby at risk. Your baby’s genes recognize these ketones as a sign that they are being born into a world where food is scarce and consequently undergo epigenetic changes in their DNA, which have been linked to increased lifelong fat storage in the neonate and older child, suggesting this may increase the risk for obesity later in life. In essence, taking a VLC approach in order to minimize weight gain or optimize body composition during pregnancy isn’t a good idea. Pregnancy is a time to relax, nourish and support your body as it undergoes the miraculous transformations involved in growing a new life.
On the flip side, there is good evidence to suggest that intake of too many carbs when pregnant may also be harmful. Excessive maternal blood glucose or sudden spikes in blood glucose can also affect the health of you and your growing baby. As mentioned before, blood sugar is shuttled directly to the growing fetus via diffusion. Lots of sugar equals bigger babies. Put simply, big babies are harder to fit out (risk of operative delivery is increased) and larger infants may also have issues stabilizing their own blood glucose levels. This puts them at risk for breathing difficulties and higher rates of admission to the neonatal intensive care unit.
Elevated blood sugars from high carbohydrate diets may also promote excessive fat storage and inflammation in the pregnant woman putting her at risk for a host of maternal complications such as pre-eclampsia, diabetes and postpartum thyroid problems. High carb diets or more specifically, high levels of fructose consumption have also been linked to an increased risk of gallbladder disease in pregnancy. This is likely due to the fact that blood sugars are naturally higher in pregnancy and the addition of easily metabolized sugars can cause increased bile cholesterol secretion, reduced bile acid synthesis, and increased bile cholesterol saturation, which can result in bile cholesterol “super saturation”. Fructose does not require insulin for uptake into the cells, it stimulates less insulin release than glucose, and it is largely metabolized in the liver and is thus metabolized differently from other carbohydrates, and its high intake leads to insulin resistance that predisposes to gallstone formation in addition to inflammation.
So what is a pregnant woman to do?
It seems that the moderate carb Paleo approach may be the most ideal approach for fertility and pregnancy. A recent study was released at the American College of Obstetricians and Gynaecologists' annual clinical meeting a few weeks ago in Louisiana. In this study, researcher, Dr. Jeffrey Russell examined protein and carbohydrate consumption during IVF treatments. His team found that women who consumed greater percentages of calories from protein had higher success rates and most optimal fertility. The study qualified low carb to be 40% of calories or less and high protein to be 25% or more. Indeed this recommendation would jive with the recommendations from most Paleo health and nutrition experts including, Chris Kresser and Stefani Ruper who both recommend moderate carbohydrate consumption during pregnancy. I recommend eating a clean Paleo diet with carb levels between 75-150g/day. You many need more if you’re breastfeeding while pregnant or are participating in vigorous exercise. In the first trimester, don’t stress if your carbohydrate levels are higher than this due to food aversion or nausea, just do your best and make smart carb choices. I recommend trying to get the majority of your carbohydrates from glucose containing sources rather than fructose. Fructose promotes excessive fat storage and can cause wild insulin spikes and crashes, which in the first trimester may exacerbate morning sickness and nausea.
Recommended foods include:
Starchy foods: Yams, sweet potato, cassava, plantains, starchy tubers
Fruits: Bananas, berries, citrus, apricots, peaches and avocados
All non starchy veggies are great choices
Foods to avoid:
High fructose corn syrup, Agave (I have a strong dislike of this highly marketed sweetener), sucrose
Eat in moderation: Watermelon, apples, grapes, pear, honey, guava and cherries.
As always, listen to your body; let its inner wisdom guide you as you navigate the fine details of your Paleo pregnancy. Don’t sweat the fine details of your diet and be sure to engage in some form of stress reduction or relaxation. I’m a big fan of the Hypnobirthing method (next post J). Take an attitude of gratitude. It’s a luxury to be able to optimize our Paleo diets for pregnancy. Remembering that women around the world struggle to feed their families can sometimes help put it all in perspective.