Every pregnant woman I’ve ever known has hated the oral glucose tolerance test. Yet, they still do it. Drinking a tall glass of sickly sweet orange-flavored glucose water on an empty stomach is thoroughly disgusting, but it, apparently, offers a rare and valuable glimpse into the state of a woman’s perinatal health.
What they’re testing for is gestational diabetes mellitus—a variant of diabetes characterized by pancreatic insufficiency during pregnancy.
Sometimes it’s a misdiagnosis. Low-carb, high-fat diets transiently increase insulin resistance. This isn’t a flaw, it’s a feature to ensure you keep burning fat in the tissues that can and preserve precious glucose for the sections of the brain that must burn glucose. But this also means that taking a gestational diabetes test while low-carb can give a false diagnosis.
Moreover, pregnancy in general throws glucose tolerance out of whack. Just like a low-carb diet can induce insulin resistance  to temporarily preserve glucose for the brain, pregnancy induces insulin resistance to preserve glucose for the fetus. This made sense when glucose was rarer, when you had to shimmy up a tree for honey  or dig for roots and tubers . In that metabolic milieu, a little insulin resistance during pregnancy was adaptive. In today’s environment, where at any given moment you’ve got a million inexpensive glucose calories within a 5-minute drive, it can cause problems.
- Excessive birth weight.
- Injuries from a rough birth.
- Low nutrient levels upon entry.
- Pre-term delivery.
- Increased type 2 diabetes risk.
- Increased C-section risk.
- Increased risk of hypertension and pre-eclampsia.
- increased risk of miscarriage.
You have two options to test for it. Well, three technically: you could just skip the test, but I don’t recommend that because GD is quite serious.
- Eat 150-250 grams of carbs per day in the week leading up to the test. This will give you a chance to shift back into sugar-burning mode.
- Ask for a “whole food” GD test. A friend of mine’s wife opted for a mixed meal containing carbs, fat, and protein instead of drinking the disgusting glucose solution, as a meal is a far more realistic test of one’s ability to tolerate glucose. The most common GD test meal involves pancakes, but those can always be gluten-free.
Okay, say you’ve got gestational diabetes, or you’re worried about getting it. What now?
Stopping it before it happens is always the ideal course of action. How can women reduce the risk of gestational diabetes?
Let’s look at risk factors. Beyond “being pregnant,” what else seems to predispose a woman to developing gestational diabetes?
- Prior diabetes. Being diabetic makes you more likely to stay diabetic. Same goes for family history of diabetes.
- Excess weight. This is another reason pregnancy sets the stage for diabetes: the unavoidable weight gain.
- Twins. Carrying twins increases the risk.
- Age. Older moms are at a higher risk of GD.
Those are difficult—maybe impossible—risk factors to change, but at least you know your risk profile. Now what can you actually do to reduce the risk?
You knew it was coming, but this really does work. Eat well, sleep lots, reduce unnecessary stress, get your veggies, eat seafood, and lead a generally healthy lifestyle.
One study  found that moderate intensity cycling for 30 minutes 3 times a week in the first trimester drastically reduced the incidence of GD in overweight and obese women.
Although we don’t have data on the relationship between gestational diabetes risk and lifting heavy things, sprinting, burpees, CrossFit, bodyweight training, gymnastics, MovNat, or high-intensity gardening, all those activities improve insulin sensitivity and glucose tolerance.
Eat well and exercise.
A recent study  found that healthy eating and exercising are more protective against GD than either alone. No word on what “healthy eating” actually meant. It was probably better than McDonald’s and Doritos, worse than grass-fed meat and sweet potatoes.
Take probiotics, eat fermented food.
One study  found that taking probiotics early on in pregnancy reduced the risk of gestational diabetes and slightly reduced birthweight without increasing preterm labor, though it had no effect on miscarriage or fetal death risk.
If you want a food source of some of these strains, most kefirs I’ve encountered in the market have L. rhamnosus GG.
Pregnant women with a family history of GD who took 2 grams of myo-inositol and 200 mg folic acid each day starting from the end of the first trimester went on to develop less gestational diabetes  than the control group who took only folic acid (6% versus 15.3%).
Say you’ve got it. What can you do?
Keep eating well.
Studies on low-carb diets in women with gestational diabetes have had fairly disappointing results. Heck, pretty much all studies of dietary interventions for gestational diabetes have been underwhelming . What might work is a focus on less refined carbs rather than a big reduction in overall carbs. I’ve said before that pregnant women need more carbs than their non-pregnant counterparts. Just make sure they’re unrefined, rather than refined. Anywhere in the range of 120-200g per day is probably best.
Check out this account  from a woman who conquered her GD by following the Primal Blueprint. Simple changes like ditching wheat, eating sweet potatoes instead of rice, and eating more veggies—alongside regular checkups with her doctor—did the trick.
But don’t “diet.”
You can change how you eat. In fact, you probably should.
You can eat healthier. Again, you’re better off doing this.
But you shouldn’t diet to lose weight. You shouldn’t cut calories, adopt any extreme eating strategies, adhere to a compressed eating window, or obsess over your weight gain while pregnant.
Focus on improving insulin sensitivity.
Unchecked insulin resistance lies at the heart of gestational diabetes. Pregnancy itself increases IR, so you’re starting from behind. The best thing you can do is review the list of 25 ways to improve insulin sensitivity  and make sure you’re doing some of them.
Not all are suitable, though. Pregnant women do have some limitations:
- Don’t go too hard or too heavy. Lift weights, safely and moderately. Don’t try to keep up with everyone at CrossFit. Don’t go for any powerlifting PRs, either. Keep things moderately intense across moderate levels of volume. Somewhere in the 5-8 rep range if weighted. Consider just doing bodyweight training , too.
- Don’t sprint. While it’s a great way to increase insulin sensitivity, carrying an entire human in your womb makes sprinting unwise.
- Keep intensity moderate. Moderate intensity aerobic exercise (30 min/day, 3x/week) really does reduce  adverse GD-related outcomes.
- Don’t fast. Now is not the time.
Snack on exercise.
If it’s at all possible, weave movement and exercise into your day. Go for walks after meals. Do a few sets of squats before you eat. This will keep your glucose tolerance primed.
Supplements and specific foods may help.
A number of studies show that certain supplements can be useful.
- Myo-inositol reduces  insulin resistance in women with gestational diabetes.
- When given to pregnant women with GD , magnesium improves insulin resistance, glucose tolerance, and other metabolic markers while reducing infant hospitalization and newborn jaundice.
- Vitamin D improves  insulin sensitivity, blood glucose, and blood lipids in women with GD.
- Selenium also improves  glucose metabolism while reducing oxidative stress and inflammation in women with GD.
- Zinc doesn’t affect birth outcomes in GD, but it does improve inflammatory markers .
- Other supplements or supplemental foods that help with insulin sensitivity (haven’t been studied in gestational diabetes), but probably don’t hurt include vitamin K2, cinnamon, ginger, garlic, turmeric (don’t forget the black pepper).
Definitely check with your doctor before beginning any supplementation during pregnancy.
Probiotics and/or fermented food can help.
A recent RCT  out of Tehran found that women with GD who took probiotics (strains: Lactobacillus acidophilus LA-5, Bifidobacterium BB-12, Streptococcus thermophilus STY-31 and Lactobacillus delbrueckii bulgaricus LBY-27) once a day for 8 weeks improved fasting glucose, reduced insulin resistance, and gained less weight than the control group.
All of these strains can be commonly found in commercial yogurt and kefir. Check the label for a list of strains.
What about pharmaceuticals?
For many years, the primary pharmaceutical treatment for women with gestational diabetes who weren’t responding to diet and exercise was an insulin injection. More recently, some doctors are giving metformin, whose potential life extension applications I’ve discussed before, to GD patients. Neither seem to be any worse for the mom or baby than the other . Another anti-diabetic drug sometimes given to women with GD called glyburide seems to increase the risk of complications .
Sadly, as of this year, we still don’t have any good research  comparing oral diabetic meds to non-pharmaceutical treatment or placebo in women with GD. Exercise caution and discuss all this with your practitioner before deciding on a course forward.
That’s my (outsider’s) take on gestational diabetes. It can often be managed using Primal principles, it’s not a death sentence, but it shouldn’t be ignored either.
What do you think, everyone? To the women readers—have you ever dealt with GD? Men—have you (in a loved one)? What worked? What didn’t?
Thanks for reading. Take care!