Treatment/Prevention of GDM
If the diagnosis of Gestational Diabetes Mellitus (GDM) is made, the first step in management is generally a referral to a dietitian to discuss dietary interventions to reduce the impact of diabetes on the pregnancy. The conventional teaching from the ADA regarding nutrition therapy in GDM is that pregnant women should continue to eat adequate carbohydrates to ensure steady weight gain (the amount of weight determined by their pre-pregnancy BMI). <http://care.diabetesjournals.org/content/30/Supplement_2/S188>
The 2002 Dietary Reference Intake Report set a minimum level of 130 g/day for nonpregnant women and 175 g carbohydrate per day for pregnancy; this is an additional 33 g carbohydrate for fetal brain development and functioning. This new minimum recommendation provides an important basis for the level of carbohydrate restriction for women with GDM.
Unfortunately, there is no scientific basis for that statement – that carbohydrates are essential for brain development or brain function, whether we’re talking about a pregnant woman or anyone else. The body is remarkably adept at utilizing various energy sources, e.g. ketones. Think about it…why would the human body be designed to be totally dependent on one energy source? The body has intricate mechanisms and backup mechanisms for nearly every metabolic process. It is implausible that a pregnancy will be doomed if one doesn’t eat at least 175 grams of carbohydrates every day?? Pure nonsense.
There is actually no nutritional requirement for carbohydrates. There are, in fact, essential fatty acids (from fat) and essential amino acids (from protein) that our bodies cannot synthesize on our own and thus must obtain from external sources, but there are no nutrients from carbohydrates that are essential to the human body.
“The lower limit of dietary carbohydrate compatible with life apparently is zero, provided that adequate amounts of protein and fat are available.”
– Institute of Medicine, Dietary Reference Intakes, 2008.
Many populations around the world thrive on very-low-carbohydrate diets, some with zero carbohydrate intake, in fact, such as the Inuit or the Massai tribe. The Inuit happen to live in a region where plants (carbohydrate sources) simply cannot survive. There are plenty more examples to disprove the archaic notion that carbohydrates are essential for brain functioning or development.
The ADA goes on to say:
Elevated glucose values, and in particular postprandial glucose elevations, are associated with adverse outcomes in GDM. Carbohydrate is the main nutrient that affects postprandial glucose levels.
Simple translation: High glucose levels are dangerous to baby; dietary carbohydrates increase your glucose level. Fact. Carrying on:
Carbohydrate intake can be manipulated by controlling the total amount of carbohydrate, the distribution of carbohydrate over several meals and snacks, and the type of carbohydrate. These modifications need not affect the total caloric intake level/prescription.
I don’t know why they’re so scared to say it, but what they should have said instead of that useless fluff is “Therefore, restricting the amount of carbohydrates in a pregnant woman’s diet will result in improvement in her serum glucose and thus reduce the potential harm of hyperglycemia from GDM on her fetus.” It appears that they are primarily fearful of weight loss during pregnancy, and they know full well that carbohydrate restriction will result in weight loss. I respect the fact that inappropriate weight loss may indicate a poor situation for the health of the pregnancy, but it’s an entirely different thing to lose weight because of a nutritional intervention that reduces the impact of GDM/hyperglycemia on baby than to lose weight from an unhealthy behavior like starvation, smoking, or other drug use. Maternal weight gain is just one piece of the puzzle. It’s just as important to monitor all the other pieces of the puzzle, including baby’s growth, baby’s organ development, mom’s vital signs, fundal height measurements, etc. It’s important to look at the big picture rather than focusing on one measurement, especially when all other measurements indicate a healthy pregnancy.
You should also know that, despite the seemingly strict guidelines and the concerned tone of your obstetric provider, there is no definite evidence of benefit to our interventions for GDM.
Although medical nutritional therapy and exercise are safe, practical, and inexpensive interventions, their impact on patient outcomes has not been conclusively demonstrated in large RCTs. <http://www.aafp.org/afp/2009/0701/p57.html>
Real-life example – Real Food and GDM
A friend of mine was diagnosed with GDM a couple years ago and asked me what my approach would be in regards to diet. She is actually a physician herself and understands human physiology (and pathophysiology) quite well, so when it came time for her to face the reality of this diagnosis, she realized that the traditional, notoriously ineffective approach to nutritional management of diabetes (gestational or otherwise) was clearly not what she wanted for her own child. I suggested a low carbohydrate, high fat (LCHF) diet utilizing real foods as the best way to control glucose levels. As I had not previously done research in this area, I did some research for her into the safety of a low-carbohydrate diet in pregnancy and found no evidence of harm. I had also recalled this podcast that affirmed that I was not entirely crazy and that I am not a lone wolf touting that a Real Food approach cannot be dangerous.
She and her family made simple adjustments to their meals fitting with a LCHF approach, and she had significant improvement in her glucoses such that her glucose remained in the normal range without any medication. She cut carbohydrate intake by avoiding things like bread, pasta, and potatoes, while using good fats like butter and olive oil for her non-starchy vegetables. By cutting carbohydrates/sugar and increasing her fat intake, she was able to revere the insulin resistance that characterizes GDM, and her body was able to properly regulate her glucose level. She actually declined her physician’s referral to a dietitian, knowing that the dietitian would only preach the standard high-carbohydrate dietary advice that got her into this situation in the first place.
In addition to normalizing her glucoses, she actually lost some weight. As you may have guessed, her obstetrician was alarmed by the weight loss, fearing that baby was somehow being adversely affected, but there was absolutely no objective evidence to support that fear. Her fundal height measurements continued to increase appropriately, and all other markers of baby’s health and her health were reassuring.
Here’s basically what her obstetrician told her: “You need to eat more, including more carbohydrates, so that we can treat you with insulin and you will gain weight.” Wait…what?!? Eat more…even though you are getting plenty of nourishment as is and you are not hungry. Eat more carbohydrates…which any physician knows will increase blood glucose. So that we can treat you with insulin…so you’re admitting that the carbohydrates are bad for someone with diabetes, because they would require medication to control their body’s pathologic response to them?!? So that you will gain weight…and worsen her insulin resistance??? Yikes.
Long story short, this friend of mine ignored that archaic nutritional advice, continued to eat a low-carbohydrate-high-fat diet for the remainder of her pregnancy, and delivered a very healthy, beautiful baby girl who is as healthy as can be, with no indication of health concerns.
Medications, including Insulin
Most cases of GDM can be managed by dietary intervention alone, but sometimes medications must be used. The powers that be would like to see improvement from dietary intervention within 2 weeks, or else may recommend a pharmacologic approach to controlling GDM.
I acknowledge that there are situations where insulin use in pregnancy is indicated. Insulin does not cross the placenta and thus mom’s circulating blood glucose level is essentially what baby is exposed to in utero. Thus, if mom’s blood glucose is markedly elevated, it makes sense to lower it by whatever means necessary.
The problem with insulin is that it is potentially dangerous. Excess insulin administration can cause hypoglycemia (low glucose), a potentially fatal condition. The strategy behind the use of insulin requires a rather steady and predictable intake of carbohydrates to balance the effect of insulin that is administered. If you give yourself insulin at the beginning of the day or before a meal, but then something happens that prevents you from eating your scheduled meal[s] (hardly an unusual phenomenon for a busy parent), you are at risk for hypoglycemia. If you are unexpectedly more physically active than on one particular day, you also are at risk for hypoglycemia. The more carbs you eat, the more insulin you will need. The higher the dose of insulin, the more at risk you are of complications from insulin. The same applies for sulfonylurea drugs, like glyburide, that could be used in place of insulin.
Another problem with insulin is that it worsens insulin resistance. Just as we develop tolerance to any other medication or substance (for example: escalating use of drugs of abuse like alcohol, heroin, etc.), your body develops tolerance to insulin, known as insulin resistance. Insulin resistance is the very process that causes diabetes, so taking insulin ultimately worsens your diabetes.
Furthermore, insulin causes weight gain, by storing excess energy (glucose) as fat. Just as too little weight gain may be bad for a pregnancy, so might too much weight gain be hazardous. There’s enough to worry about once baby is born, let alone an accumulation of even more unnecessary weight (i.e. fat mass).
Wouldn’t it be better to avoid having to take risky medications to maintain a healthy pregnancy? Simply put, if you reduce the amount of carbohydrates you eat, you will greatly reduce hyperglycemia (high glucose) and won’t need to take medication. A diet consisting of real, unprocessed foods is the most powerful and safest tool for managing gestational diabetes and is naturally low-carbohydrate. “Real” food refers to food that could be obtained right from the farm, like produce, eggs, and meat. Granted, we usually buy those things in grocery stores, but you want food items that you could find on a farm that doesn’t go through significant processing, other than the cutting/curing of meat, preparation of dairy products from milk, or pasteurization of milk, etc. Real food doesn’t have ingredients; real food IS ingredients. When you look at the ingredient label, you want to see only one item, or two items like in the case of salted butter – cream and salt. The simpler the ingredient list, the better. Avoid any food that came out of a processing plant and arrives on a grocery store shelf inside a box or bag; it’s not real food.
The most important thing regarding nutrition in pregnancy is to get adequate nutrients. It’s important to consume a variety of foods that provide adequate nutrients for metabolic processes and the development of baby. In addition, you should be taking prenatal vitamins to supplement the critical nutrients in case they are deficient in your diet. Note, however, that carbohydrate-dense products like bread, pasta, baked goods, etc. that contain flour are very nutrient-poor. In the preparation of flour, whether it be refined white flour or whole wheat flour, the grains are stripped of nearly all nutrients, so much so that flour is “enriched and fortified” with vitamins and minerals so as to artificially provide SOME nutritional benefit.
When in doubt about what to eat, choose real foods and monitor your glucose response to particular foods. Remember that starvation is not an appropriate treatment for GDM. Instead, a diet consisting of real foods will provide you and baby with the necessary nutritional support.
Isn’t fat bad for you? Isn’t fat unhealthy? What about saturated fat?
There is no good evidence that fat intake causes an increase in cardiovascular disease.
- In the Women’s Health Initiative trial, 48,836 women were randomized to a low fat diet (and high in vegetables, fruits, and grains) vs. no intervention and were followed for 8.1 years. In the study, a low-fat intervention “did not significantly reduce the risk of coronary heart disease, stroke, or cardiovascular disease in postmenopausal women and achieved only modest effects on cardiovascular risk factors” (Howard, 2006).
- Another large Randomized Controlled Trial failed to demonstrate any benefit of a low-fat diet in diabetes in reducing cardiovascular outcomes. In a study of 5145 patients randomized to intensive lifestyle intervention (low-fat, 1200-1800 kcal/day diet and exercise) vs. control group receiving basic diabetes information followed for 9.6 years, the Look AHEAD Research Group terminated the study due to futility of the intervention (Cardiovascular effects of intensive lifestyle intervention in type 2 diabetes, 2013).
Recent meta-analyses have refuted the conventional wisdom about saturated fats.
“Saturated fats are not associated with all-cause mortality, CVD, CHD, ischemic stroke, or type 2 diabetes.” (de Souza, 2015)
Another large meta-analysis looking at 347,747 patients concluded, “there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD” (Siri-Tarino, 2010).
In fact, there is evidence that saturated fat actually decreases cardiovascular disease.
- The influence of diet on progression of coronary atherosclerosis over 3.1 years was examined in 235 postmenopausal women, with specific regards to saturated fat intake. Despite a positive correlation with smoking, the quartile with the highest saturated fat intake had the least progression of coronary stenosis. That quartile also had significantly higher serum HDL and lower serum triglycerides. Carbohydrate intake was “strongly positively associated with progression” of coronary stenosis.
In postmenopausal women with relatively low total fat intake, a greater saturated fat intake is associated with less progression of coronary atherosclerosis, whereas carbohydrate intake is associated with a greater progression. (Mozaffarian, 2004)
“The deleterious effects of fat have been measured in the presence of high carbohydrate. A high fat diet in the presence of high carbohydrate is different than a high fat diet in the presence of low carbohydrate.” Richard Feinman, PhD
Is ketosis dangerous in pregnancy?
Nutritional ketosis is not a dangerous condition, but rather a normal physiologic response to a fasting state in which the body utilizes fat stores for energy when glycogen stores are depleted. Ketosis probably occurs frequently in pregnancy and without ill effect. According to the “Standards of Medical Care in Diabetes – 2016” published by the American Diabetes Association (ADA), “Pregnancy is a ketogenic state.” <http://care.diabetesjournals.org/content/suppl/2015/12/21/39.Supplement_1.DC2/2016-Standards-of-Care.pdf>
Though the so-called “experts” advise to avoid ketosis, there is no evidence demonstrating harm to the baby. In fact, the fetal brain gets approximately 30% of its energy from ketones.
- Institute of Medicine (US). Panel on Micronutrients. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids. Panel on Macronutrients Panel on the Definition of Dietary Fiber, Subcommittee on Upper Reference Levels of Nutrients, Subcommittee on Interpretation and Uses of Dietary Reference Intakes, and the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition Board. National Academies Press, 2005.
Ketosis is a common occurrence in pregnancy, probably owing to the increased metabolism driven by the developing fetus, unless the pregnant mother is eating a continuous supply of carbohydrates. That said, until we have further research into the safety of ketosis in pregnancy, I wouldn’t advise an aggressive pursuit of ketosis while pregnant.
There is a profound difference between nutritional ketosis and diabetic ketoacidosis. It takes rather significant carbohydrate restriction just to get to nutritional ketosis, which is a normal physiologic process that actually has immense benefits to our health. Ketoacidosis, on the other hand, is a pathologic state that occurs in severely uncontrolled diabetes (usually Type 1) in the setting of insulin deficiency, not by carbohydrate restriction.
“During very low carbohydrate intake, the regulated and controlled production of ketone bodies causes a harmless physiological state known as dietary ketosis”.
- Manninen, A. (2004). Metabolic effects of the very-low-carbohydrate diets: Misunderstood “villains” of human metabolism. Journal of the International Society of Sports Medicine, 1(2): 7-11.
Need further proof that carbohydrates are not an essential nutrient?
I did a 7-day fast (water and bone broth only) during my 7-day workweek taking care of acutely ill hospitalized patients with no ill effects to myself, and I followed my usual workout routine without a hitch. Need more proof? Go measure the amount of carbohydrates in whale meat and blubber, and figure out how many Inuit living in the Arctic are getting 130 grams of carbohydrates per day or how many suffered impaired brain development born to Inuit mothers eating a traditional diet relative to how many Americans did while following the dietary guidelines to a tee.
Don’t I need fiber?
Vegetables are an excellent source of fiber and will provide all the fiber you might need. If you need extra fiber, you could utilize a fiber supplement such as psyllium.
Don’t I need carbohydrates? Aren’t carbohydrates essential for the brain and for brain development?
No, this is a common myth about human physiology.
In the absence of carbohydrate intake, the human brain can get approximately 80% of its energy needs from ketones. The rest of the energy requirement can easily be obtained from glucose produced by a process called gluconeogenesis.
There is no nutritional requirement for carbohydrates. There are essential fatty acids (from fat) and essential amino acids (from protein), but there are no nutrients from carbohydrates that are essential to the human body.
“The lower limit of dietary carbohydrate compatible with life apparently is zero, provided that adequate amounts of protein and fat are available.” – Institute of Medicine, Dietary Reference Intakes, 2008.
Aren’t whole grains good for me?
The vast majority of so-called “whole grain” foods are still highly processed. Grains increase blood glucose as much (and sometimes more) than pure sugar, thereby posing a threat to baby in utero.
“Consumption of whole grains has not been associated with improved glycemic control in persons with diabetes; however, as for the general population, individuals with diabetes should consume at least half of all grains as whole grains. Large prospective cohort studies, but not randomized controlled trials, report that consumption of whole grains is associated with a reduced incidence of type 2 diabetes.”
Diabetes Metab Syndr Obes. 2014; 7: 65–72. <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3938438/>
On the other hand, whole grains may provide slightly better nutritional value than refined grains, but that essentially means that whole grains are slightly “less bad” than the alternative. (A bit like the bipartisan choices in the 2016 presidential election)
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