Is Keto Dangerous While Pregnant, Breastfeeding, or for Children?

A question I’ve come across seemingly increasingly in the past few months, is a variation of, is it safe for kids to eat keto, including women during pregnancy and breastfeeding? This is where a simple disambiguation between a well and poorly formulated diet should end the discussion but let’s dig a little bit deeper into the concerns themselves, studies on children, the validity thereof, what a good diet is and context.

Getting Pregnant and PCOS (Polycystic ovary syndrome):

One of the applications of a well formulated ketogenic diet has been in treatment of PCOS with much success, though more research is needed. You can search for yourself to find more info on this and the specifics with lots of other blogs and anecdotes covering it out there, but between weight loss and improved hormone regulation from better food choices it’s a way to manage symptoms and issues associated with the disorder. Many women who see improvements have noted they end up with a surprise pregnancy after starting low carb. Though usually planned or at least semi-planned, you can find near endless anecdotes of despite several years of trying, a sudden ketobaby happened after a few weeks or months of low carb. Just search through and /r/ketobabies for personal accounts thereof.

If you’ve done prior research into keto, you should already know that improvements in endocrine function are one of the benefits with plenty of evidence to support it. So if you’ve found yourself with a surprise baby thanks to keto the next question is, can you, should you, or is it dangerous to continue while pregnant?

Ketosis and Pregnancy:

Thanks to Japan and low carb as a treatment for diabetes we do have some research done regarding the application of a low carb diet in pregnant mothers on ketone levels and their role. Aside from this, comparative research is unlikely to happen because of ethics and perceived risk. However we can also look to semi-modern people groups that ate little to no plants or carbohydrate such as the Inuit and Masai who have had much research done on their cultures that thrived in their way of life.

To begin with, most women who suffer from morning sickness tend to be in and out of ketosis at least transiently in the beginning regardless of diet make up. Add to that food aversions, lack of appetite, and general nausea and you’ll have a lot of women eating very little or sporadically in early pregnancy or sometimes throughout.

Ketosis itself isn’t an abnormal state of being for the body, it’s something that most cross into at least to a small amount overnight, and in longer periods of carbohydrate restriction such as a ketogenic diet. This adaptation is important in humans in order to fuel our energy hungry brains without needing to feed on carbohydrates constantly. Nothing is inherently harmful about the presence of ketones in your blood to you nor your fetus, so if the ketones are not the problem, and carbohydrates are not an essential nutrient, what’s the worry?

One of the most valid worries is with doing keto for weight loss, kind of. If you’re restricting calories it’s not really going to impact you in the first 6 months of pregnancy as the fetus is not gaining any appreciable amount of weight, not until halfway through the pregnancy does weight begin nearing half a kilogram. Near the end of the pregnancy and into breastfeeding you’re looking at about  300-500+ extra calories per day, eating at maintenance you could easily continue safely losing weight through these phases if you have the body fat to support the energy demands. The danger however, in restricting intake of calories, you’re also restricting the intake of micronutrients. At a time where brain, nervous system, and other vital systems are developing in the fetus or newborn, you don’t want to restrict the intake of micronutrients by proxy of restricting calories. So this leads us to, what’s really important.

Essential Nutrients:

This section is big, and was originally larger, feel free to skip, TL;DR, follow our general advice.

At a basic level these are the building blocks of life. Included are amino acids (proteins), fatty acids, vitamins, and minerals. This is where the science clears it all up. Regardless of what you want to label your diet, be it paleo, high carb, low carb, vegetarian, Mediterranean, 30 bananas a day, etc. the necessary nutrients do not change. The form you may be receiving them in and amount you may need may vary due to how they interact or convert. Often one of the first arguments to come up after “You need carbs!” is that keto is unhealthy, but rarely will anyone elaborate beyond “fat bad; healthy carbs good”. I will not go as far as to say a ketogenic diet is universally better or healthy in this regard. Just as you can have a well rounded keto diet you can also have one that is very deficient in nutrients, which I will get into with more detail later with the studies, especially drinking BPC and eating ketofied snacks. Since eating fat and protein is relatively easy, the rest of the micronutrients is where it becomes even more important. I’ve included in each section a link to a table from the National Institutes of Health with a table of the best sources of micronutrients. You can find very keto friendly options take up a large portion of the tables.

Eating a diet based primarily on nutrient dense foods, you can very easily meet your micronutrient needs at any age while eating a keto diet. Feel free to jump ahead to more on common concerns ⬇.

Protein – Essential amino acids are not able to be synthesised by our bodies and do require to come from an outside source. These are used in nearly every single bodily process and are the building blocks for tissues of all kinds, hormones, enzymes, hair, skin, muscle digestive tract, heart, blood vessels, the list is near endless. The most important nutrient hands down, without it you cannot live.

Fat – Essential fatty acids must also come from dietary sources, they play a role in hormone production, fuel, cell construction, and other functions.

Omega-3, (DHA) – We’ve all heard that omega 3 fatty acids are healthy for us but why are they so important? DHA is one of the most important building blocks for the human brain outside of cholesterol and vital in the development of the retina. Unfortunately our ability to synthesize DHA is quite low from other omega 3s, ALA to EPA less than 5% efficiency and less than 0.5% ALA to DHA. As all plant forms of omega-3s are ALA outside of ones recently discovered in some algae, their usefulness is significantly less than the label on the flax seeds would have you believe. So what can we do? Well, there are concerns of oxidation of the fats in a supplement form as well, this leaves us with whole foods. Fish, more specifically sardines and salmon would be some of the absolute best sources, luckily red meats have a good amount of omega-3s available as well so you’re not too limited in choices, if you’re not a fan of either of these taking a good DHA supplement is a good way to make sure you’re getting at least some in your diet.

Iodine – We’ve got a whole article on this one. A vital nutrient in neural and brain development as well as host of other functions, there’s a reason it’s been added to grains and salt. Deficiency and goiter is a real problem, the best sources for it will be seafood, fish, and eggs, and supplementation is fairly straight forward should you believe you need it. Give Dustin’s article a read for more info.

Selenium – Like iodine, this is a very important player in development and regulation of thyroid as well as DNA synthesis, protection from oxidative damage and other functions. Your best options for selenium are fish, beef, chicken and eggs or at the top, rather than need to supplement selenium you could easily use a single brazil nut per day to meet the requirement if you didn’t feel you were getting enough from whole foods.

Zinc – Another trace element that plays a vital role in development and continued support of systems. In early development DNA synthesis and enzymatic production will be the most important roles, later on it plays a role in sensory organs and immune function. So where do we get it? Seafood beats everything hands down and synergizes well with selenium which makes some of that scary mercury content in fish inert. There are varieties to avoid but the higher the selenium content in the fish, the better. If you’re deficient, supplement it, but you can fix this one with diet alone and whole foods.

Iron – Important in haemoglobin production, iron comes in two forms, heme iron and non-heme iron. Heme iron is found only in animal products and is preformed, making it ideal as it’s readily absorbed while non-heme iron is less bioavailable on top of the plants the occur in also contain anti-nutrients such as polyphenols that inhibit uptake. Most of the other good sources of iron outside animal products are fortified cereals and grain products.

Calcium – We all know the importance in bones and teeth and other structures built with calcium but does it matter where it comes from? As with every other mineral, it’s absorption is often hampered by oxalates or other anti-nutrients that reduce it’s absorption, as such you will not see spinach on the table below. Another fascinating worry about the ketogenic diet is the increase (usually from low to adequte) protein intake also see an increase in calcium secretion in the urine, this has been know for a long time. The hypothesis has been used from the alkaline diet to vegan propaganda telling you that you’ll eat away at your bones if you eat animal protein. The opposite has actually since been observed. Proper protein intake helps retain or increase bone density as well as increases calcium intake. Once again many good choices here for calcium, most being dairy which is selectively acceptable, dark greens and fish unless you’re eating nose to tail and including bone broth most muscle meat isn’t the best source, ground beef marginally better. The best option is to include the small bone in fish as often as you can or dark green non-starchy vegetables.

Magnesium – Magnesium is another one that should be supplemented in nearly any diet, keto or not. Between mineral depletion in soil and water sources supplementing magnesium is beneficial for many aspects of your body’s operation from electrical impulses, to bone health, mental well being, and mood. Though it is one of the most abundant minerals in the body, only about 30-40% of magnesium in food is bioavailable adding a supplement is advisable. In terms of absorption glycinate > malate > citrate, with citrate as the easiest to find. Nuts, leafy greens, avocado and meat, especially fish will be your best dietary sources..

Thaimine (B1) –  Thiamine supports metabolism of energy, cell growth, and as most other vitamins therefore aids in proper development. Primarily found in pork, fish and seafood in larger concentrations fairly easy to hit with diet alone. Since it’s more important in carbohydrate metabolism meeting it through diet isn’t quite as important as if you were eating higher carb.

Folate (B9) – Another vitamin that has been added to foods to fortify them, folate is a B vitamin involved in DNA, RNA production, cell division and metabolization of amino acids. 400 mcg is the suggested daily intake for adults, and 600 mcg for pregnant or 500 mcg breastfeeding women, it’s even suggested to intake 800-1200 mcg daily for months prior to conception, since it’s the first few weeks where it’s important in preventing neural tube defects. It’s unlikely it’s completely necessary to hit these levels unless you’re previously deficient, but it’s imperative to proper development. Now before you go and supplement it, most supplements contain folic acid, which despite the usage is not the same as folate, whole foods will always be the best source. More info on the difference here and here.

Here is a link to the NIH entry on folate. Though they do list folate from food as less bioavailable than those fortified folic acid, folic acid is limited in it’s ability to be converted to a usable form of folate and there are concerns over excess left unmetabolized in the blood stream, so whole food especially liver wins out with dark leafy greens a close second.

Other B vitamins – Rather than address each of these I’m lumping the last few Bs together. We all know B vitamins are important, vitamin B12 deficiency is a big problem and many people take a multivitamin “just to be sure” for the rest. On a keto diet, you shouldn’t have to worry about being deficient in any of the major B vitamins (B2, B3, B6),as meat contains the best source and form of all the B vitamins while B12 is exclusively found in animal products. If you choose to take a vegetarian approach to the diet it’s best to supplement and adjust intake accordingly.

Vitamin A – Form matters for vitamin A, retinols (preformed) being readily utilized, while beta carotenes need to be formed into retinol. “Because the body converts all dietary sources of vitamin A into retinol, 1 mcg of physiologically available retinol is equivalent to the following amounts from dietary sources: 1 mcg of retinol, 12 mcg of beta-carotene, and 24 mcg of alpha-carotene or beta-cryptoxanthin. From dietary supplements, the body converts 2 mcg of beta-carotene to 1 mcg of retinol.” from NIH, on the table you can see liver and spinach being 2 of the top 3 options even going a bit over the top. Luckily Vitamin A gets stored in the liver and does not need to be consumed daily so overdosing with regular cycling of it in and out of the diet is near impossible. Most cases of Vitamin A toxicity come out of people taking multiple supplements (such as cod liver oil + multivitamin) for extended periods.

Vitamin E – Primarily an antioxidant, in a low carb environment with reduced oxidative stress less will be required. If you are concerned, nuts as well as dark leafy greens are great sources..

Vitamin K – Plays a role in blood clotting. More important to keep a consistent intake as fluctuations up or down may affect clotting. Lots of options keto friendly, NIH table for reference. Vitamin K isn’t as simple on the surface as it would seem, there is evidence that points towards K2 being the more important component that extends far beyond just blood clotting and is primarily found only in animal products and natto.

Vitamin D – This one isn’t very diet related, but is still quite important. Most people in our modern society do not get enough sun and are found to be deficient in Vitamin D. Prevailing suggestions for daily intake are ranging from 400 IU to 800 IU are likely woefully inadequate and depending on sun exposure a range from 1,000-5,000 IU would be more likely beneficial to most adults. The safe upper limit from Vitamin D points to 10,000 IU but there doesn’t seem to be any harm in exceeding that level. Breastfeeding infants are suggested to take 400 IU/day in order to promote proper bone growth and development as well as to prevent rickets. Formula has been required to be fortified with Vitamin D for exactly this reason. So while some animal products do contain it, depending on where you live on the planet, and how much skin you expose to the sun you should probably supplement this one. More info on examine.

If you clicked through to the charts, you’ll notice in most of the grain and cereal products in the tables are enriched or fortified. This means all those super healthful whole grains, and cereal products are only healthy because they’ve been either added to or have had nutrients added back lost in processing. If it wasn’t for the government mandating that these be enriched, the amount of micronutrients and vitamins in these products would be significantly lower to the point nearly all regular diets that include them would be significantly deficient in many essential nutrients. It’s not the grains that make them healthy, it’s what the law forced them to add in to it.

So what do you eat? We’ve got you covered. Keep it simple with whole foods, a variety of fatty meat, fish (sardines), eggs, seafood, dark green veggies, avocado, and offal. I’ll give some more specific suggestions down below. If you’re doing vegetarian keto, make sure to supplement accordingly.

Concerns for Children on Keto, Fact or Fiction?

If we can easily meet all the essential nutrients through diet while being keto, are the concerns for children still valid? In context, yes. Since there has been years of research on keto diets as a treatment for epileptic children we can look to them as reference, and this is where the problems lie. There are a few well researched lists of detrimental effects of a keto diet, some are based on nutrition myths while the rest are contextual and none of which should be real concerns with a well formulated diet. So let’s address a couple of them.

Progressive bone mineral content loss in children with intractable epilepsy treated with the ketogenic diet .

Let’s tackle one of the big ones first. This is very much to be expected when you look in the the makeup of the diet.

Children in the study were prescribed a 4:1 (by weight fat:carbohydrate and protein)”

This is very typical of epileptic ket diets and one of the biggest reasons we see issues with it. You can see that fat is four times protein + carbs by weight, so we are looking at 27:4 or about 87% fat to 13% carbs and protein calories.Seeing protein restricted this low, though noted they should be meeting RDA, that is already very low, not only are you missing out on insulin growth factor you have near or very inadequate protein intake.

In general, the KD was provided as 3 meals, with 1 snack for children < 4 y. All children were supplemented with one multivitamin with minerals (at a vitamin D concentration approximately recommended for age) (11) and additional calcium and phosphorous at recommended intake for age (11).“

From the remainder of the food intake it’s hard to tell what the food is, but if it’s anything like the other epileptic studies very little if any is real whole foods and much of it is oils. Trying to use a multi-vitamin as a bandaid and supplements to make up deficiencies in food intake is not going to be enough to fix the issue. We know that calcium uptake is enhanced by protein consumption, so restricting protein so low in order to beat seizures and inflate ketones levels is not a recipe for good growth.

We see the same issue in this study, where the diet make up mirrors the typical 4:1 ratio of fat to protein+carbs, despite what they believe to be adequate nutrition is still highly restricted protein intake. The dangers of low protein intake are well documented and include bone and other tissue growth, it’s not just for muscle. If anything this is a condemnation of too high at is not healthy for the average person, the trade off to treat epilepsy is not a safe diet for a normal person.

We have another study with similar issues and low protein count in the blood.

Despite supposedly adequate nutrition Every child was provided an average energy intake of 60–80 kcal/kg per day, with 1–1.5 g/kg of protein supplemented with potassium citrate, multi-vitamins and essential minerals.” issues still occurred. Let’s take a look at their food.

The first 30 children, starting between October 2004 and June 2007, had self-prepared meals planned according to the Ketogenic Diet Meal Planner (designed by Liao using Chinese recipes). The next 28, starting between September 2007 and September 2008, used predominantly KetoCal (Nutricia) ketogenic formula as part of their diet. To increase the palatability and variety of the diet, Qitong ketogenic liquid milk (Zeneca), Qitong ketogenic cookies (Zeneca) and packaged ketogenic set-meals (Zeneca) were developed by Liao, and added in as supplements to the Ketogenic Diet Meal Planner since October 2008. All three Zeneca products have a lipid-to-non-lipid ratio of 4:1, with 60% of the total lipid long-chain triglyceride (LCT) and 40% medium-chain triglyceride (MCT).”

Except for presumable a small portion of the children we see little to no real food and micronutrients trying to be met by supplements. This is far less than ideal.

Thirty-nine (12.3%) children experienced hypoproteinaemia. Except one 12-year-old case, all hypoproteinaemia cases were found in children below 5 years. Food refusal was often reported by parents to precede hypoproteinaemia.”

That’s pretty profound to see so many with issues likely if nothing else from poor food quality and low protein intake. More importantly this is one of the studies that gives us a look at some of the supposed deaths caused by keto.

During the follow-up, 10 children died, among which 3 had withdrawn from the KD for more than 6 months before death, 2 died of status epilepticus, 2 died of pneumonia, 1 fell from height, and for the remaining 2 cases, parents were unwilling to disclose the cause of death.”

Nothing diet related here causing death, just a lot of correlation.

Sorting through the other concerns they are common issues not exclusive to keto.

  • Electrolyte intake, including: Arrhythmia, heart palpitations, impaired mood, cognition/brain fog, muscle cramps as well as constipation.
  • Protein intake: Thinning and hair loss can happen with any major diet change but is directly related to both low calories and low protein intake especially biotin.
  • Fiber intake: With most of the complaints with constipation there is a large amount of fiber present that may be better off reducing in addition to magnesium supplementation.
  • Cholesterol: Concerns over hyperlipidemia are based on old data/view of lipids and typical of transient hyperchlesterolemia in those experiencing weight loss. For more info on the current science, this is long but worth it from Peter Attia. As well as a bit more in depth as it happens cholesterol tear down from Dave Feldman.

The concerns are very real, and valid in context. That context being a therapeutic diet for the treatment of epilepsy and the tradeoffs of a healthy diet of whole foods for protein restriction and lots of liquid fat. This is not a well formulated diet. Keto is not universally a good or healthy diet just by magic ratios, you need sufficient context to the person and their nutritional needs, and this is where whole food choices beat out ketofied junk and bulletproof coffee.


Pregnancy & Breastfeeding

I am not a doctor, so if you have any real concerns, please review with a medical professional, these are just general recommendations. During early pregnancy and prior to conception foods higher in folate such as liver and dark leafy greens will be important to avoid neural tube defects as well as provide the micronutrients that will be deposited in the placenta to nourish the fetus over the coming months. Prenatal vitamins may not be necessary, plus, supplementing with a multivitamin has it’s own risks. A nutrient rich diet will be a much better way to get in your nutrients in and your calories too. Often the calcium and magnesium in the vitamin will block absorption of the iron that most useful item from the supplement. If you can meet it with diet you should, if you’re deficient, then take supplements as necessary, but don’t blanket supplement with a multi if you can help it. DHA, iodine and vitamin D are important throughout, eat your liver and sardines!

Glucose tolerance test: you will very likely get a false positive on a glucose tolerance test in keto. If you’re unable to turn it down, you can increase carbs to 125g for three days prior in order to pass, otherwise opt for A1C testing or home monitoring of glucose if possible.

Protein: suggested higher end of recommended intake -1.0-1.2g/lb lean mass, throughout both pregnancy and breastfeeding. From building the placenta and the fetus, to providing oxaloacetate to convert into lactose in the milk supply, protein does it all.

Carbs: Later into the pregnancy and for breastfeeding, if you want to stay keto, your carb tolerance will increase, and many can get away with increasing carbs to 40-50g, you can choose to use this to add more dark green veg, seafood, shellfish or offal to your diet for micronutrients. You can go as low as zero or as high as you wish, just adjust your food choices accordingly for micronutrients.

Calories and weight loss: This can be a great time to lose some extra weight if done right but you run the risk of restricting micronutrient intake in conjunction with calories. Entirely depending on your body fat to provide energy as necessary, luckily additional energy requirements are fairly low. There’s no reason to put on 30-60lbs during pregnancy, it’s stressful on both your body and the fetus, especially when coupled with gestational diabetes or other complications. You can have a very healthy pregnancy only adding on an extra 15-20 lbs total without adding extra fat. Once breastfeeding it’s a very easy way to let the pounds melt off, you burn more breast feeding than you do in pregnancy. If you have the body fat to support it normal maintenance calories should give you enough deficit.

  • >25% bf – easily eat at small calorie deficit first trimester and at normal maintenance following.
  • 17-22% bf – Maintenance in the first trimester +100-200 calories~ in second trimester + 300-500 in third and for breastfeeding
  • <15% bf – you run the risk of limited supply by the time you are breastfeeding because of hormone levels and may want to eat at a surplus until you’re at least above 15%.

Above all else, use this time to eat well, good nutritious whole foods. While many get away with eating junk and enough for two adults during pregnancy this is not a time to indulge. Eat for your health as well as the fetus, a good foundation is best for both of you during pregnancy and in to breastfeeding.

Babies & Toddlers

Despite the fact that a baby’s diet is exclusively breastmilk or formula initially which is high in lactose, they’re still ketogenic in order to meet the energy demands of their brain. A newborn uses about 75% of its daily energy expenditure just to run it’s huge brain. While the digestive system and the rest of the plumbing are being prepared for food later on. Even in toddlers and older children, they will reach ketosis much faster than adults. At the early stages it is very much business as usual to be in ketosis the majority of the time as a support for neural function and massive energy sink. So much so is the reliance on fat as both a construction material as it is a fuel the baby fat is unique to humans in such a way to provide for it. So while breast milk is the perfect food for the baby, around 6 months, it’s no longer able to keep up with energy needs fully and we need to feed the growth of the brain further. This means energy and nutrient density is paramount. Where is the best place to get this? Meat. Small gut, large brain, best use of limited surface area with energy and nutrient dense foods.

Though breastfeeding may continue to 2-5 years of age, babies are not typically fed exclusively at breast for much longer than 6 months. WHO does recommend breastfeeding to 2 years of age primarily for immune system support. What should you feed your child during the transition period? Baby led weaning is gaining popularity and is probably the most organic way to start the process, very similar to what has been suggested in Canada for the last couple decades. To do so, slowly introduce them to your foods as they show interest. Starting with liquids, to soft foods and eventually solids as they are curious of your food, they will try it themselves. No different from any regular diet, instead avoiding vegetable mash and fortified hot cereals for broth, fatty meat, eggs, and fish. Their diet shouldn’t be different than yours except with a bit more focus on micronutrients and protein. They should be eating what you eat, unless what you’re eating doesn’t offer adequate nutrition. A bit more on this topic from an evolutionary perspective.

Children, Adolescents, and Teens

For older children into the teen years the only distinction may be to never limit protein or calories while growing. Besides micronutrient availability, the protein content of food is very important as insulin growth factor synergizes well with muscle, tissue and bone development. Carbs are not necessary to max out the growth but adequate or even higher intakes of protein are. Should you have older children or teens who’re already overweight starting keto hoping to help with weight loss and appetite control, the same idea applies, reduce dietary fat, but focus on lean nutrient dense protein to support growth as well as some fat and cholesterol intake for hormone support. Just like women, seniors, and high performance athletes, growing kids will have higher protein requirements, ad libitum should be safe, but erring on the side of 1.0-1.2g/lb lean mass should be the goal. For calorie intake there isn’t a rule of thumb or a good way to calculate as growth rates and times vary between individuals. Luckily if good eating habits are learned, the amount of food consumed should be much easier self regulated than if bad habits have formed.

Beyond Puberty

Now you’re a young man or woman ready to tackle the world! Once majority of growth is completed there’s no reason to treat a young adult as different than a 30 year old as far as nutrition goes, past the growth stage the dissimilarities fade and the KETOGAINS calculator comes into play. Eat well and be active. If done proactively that should follow through to much later in life with overall health, and longevity.