The Danger of Protein During Pregnancy

At PerfectHealthDiet.com we’re advocates of protein restriction. We recommend:

  • Avoiding all protein-containing plants, as plant proteins tend to be toxic;
  • Striving to eat fatty, not lean, meats and fish, in order to keep protein intake down and fat intake up.

Protein restriction helps protect against viral and bacterial infections by promoting autophagy, the process of intracellular protein scavenging, digestion, and recycling.  During autophagy, bacteria and viruses, as well as junk human proteins and damaged organelles, are digested.  Autophagy has been strongly linked to longevity [1] and is protective against many diseases.

Our advocacy of low protein intake separates us from many other Paleo bloggers.  Loren Cordain, the dean of the Paleo movement, has long advocated consumption of lean meats.  Although he has moderated his stance somewhat, the front page of his site still places lean meats first among his favored foods:

Learn how a diet based on lean meats

The Paleo Diet is a way of eating in the modern age that best mimics diets of our hunter-gatherer ancestors – combinations of lean meats

(The other major difference we have with Dr. Cordain is his exclusion of starchy foods from a “Paleo” diet, even though starchy tubers have been part of the ancestral human diet for 4 million years. But that is a story for another day.)

Those who have read the pre-publication draft of our book know that we place high store on human breast milk as an indicator of the optimal composition of the human diet.  Human breast milk provides only 7% of calories in the form of protein. (Carbs are about 38% and fats about 55%.) One can debate whether 7% is the right level of protein for adults; but, if the principle of natural selection is sound, it must be that infants need a low-protein diet.

Science bears this out.  As our book notes, diets containing 20% of calories as protein are highly toxic to infants. Pre-term infants fed 20% protein diets had more fever, lethargy, and poor feeding than infants fed 10% protein diets, and lower IQs at ages 3 and 6 years. [2] Even a slight increase in the protein content of formula, from 7% to 9%, significantly increased the likelihood that babies would be overweight by age 2. [3]

Given our skepticism toward high-protein diets, especially for babies, we were pleased to see Dr. Cordain in his most recent newsletter [The Paleo Diet Update v6, #20 – Protein Intake for Pregnant Women] acknowledge the dangers of high protein intake by pregnant mothers. Dr. Cordain advises a pregnant mother:

[Y]ou probably should increase your fat and carbohydrate consumption, and limit protein to about 20-25% of energy, as higher protein intakes than this may prove to be deleterious to mother and fetus for a variety of physiological reasons….

“Protein intakes above this [25% of total calories] threshold may affect pregnancy outcome through decreased mass at birth and increased perinatal morbidity and mortality.” [4]

The physiological basis for this aversion stems from a reduced rate of urea synthesis during pregnancy that is evident in early gestation [5] as well as increases in the stress hormone cortisol [6]. Hence, pregnant women should include more carbohydrate and fat (i.e. fattier meats) in their diets and limit dietary protein to no more than 20-25% of their total caloric intake.

What are the long-term effects of a high-protein diet during pregnancy on the offspring?  In long-term follow-up studies of the adult children of mothers who ate high protein diets while pregnant between 1948 and 1954, it was found that by age 40 offspring commonly had high levels of the stress hormone cortisol [6] and high blood pressure [7,8].  The effects of faulty maternal diets can be long-lasting.

At PerfectHealthDiet.com, we think 20% is still likely to be a bit more protein than is desirable. We would advise pregnant mothers to restrict protein to about 15% of calories and to strive to obtain 30% of calories as carbohydrates.  As long as adequate carbs are obtained, there is only a modest need for protein and as little as 10% of calories as protein may be sufficient.

Note that this advice is very close to the ratios of 30% carb, 15% protein, and 55% fat that we recommend to adults and children generally.  Pregnant women may benefit from slightly more starch and slightly less protein than others; but on the Perfect Health Diet, pregnancy should not require a significant change in eating habits.

[1] Jia K, Levine B. Autophagy is required for dietary restriction-mediated life span extension in C. elegans. Autophagy. 2007 Nov-Dec;3(6):597-9. http://pmid.us/17912023.

[2] Goldman HI et al. Clinical effects of two different levels of protein intake on low-birth-weight infants. J Pediatr. 1969 Jun;74(6):881-9. http://pmid.us/5781798. Goldman HI et al. Effects of early dietary protein intake on low-birth-weight infants: evaluation at 3 years of age. J Pediatr. 1971 Jan;78(1):126-9. http://pmid.us/5539071. Goldman HI et al. Late effects of early dietary protein intake on low-birth-weight infants. J Pediatr. 1974 Dec;85(6):764-9. http://pmid.us/4472449.

[3] Koletzko B et al; European Childhood Obesity Trial Study Group. Lower protein in infant formula is associated with lower weight up to age 2 y: a randomized clinical trial. Am J Clin Nutr. 2009 Jun;89(6):1836-45. http://pmid.us/19386747.

[4] Speth JD. Protein selection and avoidance strategies of contemporary and ancestral foragers: unresolved issues. Philos Trans R Soc Lond B Biol Sci. 1991 Nov 29;334(1270):265-9; discussion 269-70. http://pmid.us/1685584.

[5] Kalhan SC. Protein metabolism in pregnancy. Am J Clin Nutr. 2000 May;71(5 Suppl):1249S-55S. http://pmid.us/10799398.

[6] Herrick K et al. Maternal consumption of a high-meat, low-carbohydrate diet in late pregnancy: relation to adult cortisol concentrations in the offspring. J Clin Endocrinol Metab. 2003 Aug;88(8):3554-60. http://pmid.us/12915635.

[7] Campbell DM et al. Diet in pregnancy and the offspring’s blood pressure 40 years later. Br J Obstet Gynaecol. 1996 Mar;103(3):273-80. http://pmid.us/8630314.

[8] Shiell AW et al. High-meat, low-carbohydrate diet in pregnancy: relation to adult blood pressure in the offspring. Hypertension. 2001 Dec 1;38(6):1282-8. http://pmid.us/11751704.

Leave a comment ?

60 Comments.

  1. Low Carb Age » Protein Intake: Special Cases - pingback on July 12, 2010 at 10:42 pm
  2. The Paleo Rodeo #017 - pingback on July 21, 2010 at 3:04 am
  3. IMO lose weight is not impossible if you keep doing exercises consistently and don’t ever eat the fast food. Unfortunately, .

  4. whey protein is great for supporting those muscles that are workout heavily’.,

  5. Hi,

    I have just spent the last two hours scouring your site and my head is filled to the brim. That said, my question is a very simple one: how to subscribe to your blog? Am I missing a button to click somewhere that can send me daily/weekly udates like “The Healthy Skeptic”?

    Can’t wait to buy your book!

    Thanks,
    Claire

  6. Oops! Just realized where I posted this. Will have to spend some time getting acquainted with the site.

    Claire

  7. Hi Claire,

    Well, we have an RSS feed button in the upper right. You can view RSS content in Outlook, where it comes to you just like email, or other RSS readers.

    We’ll probably have to come up with an email update too, but haven’t done that yet.

    Best, Paul

  8. Okay, it was just explained to me how to do the RSS feed. Nothing wrong on your end.

    Claire

  9. On the subject of RSS feeds, does anyone else have a problem with not receiving all of the comments in their RSS feed? I use Google Reader, and some of the comments don’t seem to make it into the feed. When I clear out the feed (mark all of the comments as read) and come back at a later date, the feed will update with a maximum of 10 new comments, even if there have been 11, 16, or 42 new comments posted.

    Does anyone else have this problem, or know how to fix it? I hate the idea of missing a valuable comment.

  10. Hi Sam – Yes, I have that problem too. I will have to consult with someone more technically knowledgeable than I to fix it.

  11. Sam, couldn’t agree more about missing comments, especially here.

    I haven’t noticed that Google Reader limits the number of comments, but sometimes, the same set of comments will show up again after I’ve marked them all as read???

  12. Paul,

    I would be very interested to hear your response to Don’s reaction to your arguments on protein restriction:

    http://donmatesz.blogspot.com/2011/01/protein-restriction-and-longevity-my.html

  13. Hi Todd,

    I left a comment there, http://donmatesz.blogspot.com/2011/01/protein-restriction-and-longevity-my.html?showComment=1294173244658#c6839881183139427240.

    Clearly this is a big issue that could consume many blog posts. But I’m delighted Don has tried our diet and initiated a discussion. It’s definitely an interesting topic.

    Best, Paul

  14. Oops, just noticed your response at his site, please
    ignore.

  15. I respect Dr Cordains advice – mostly – as i have seen very good opposing viewpoints regarding saturated fats. More fats during pregnancy seem like good advice – however, Dr Cordain also speaks against dairy as a paleo foodstuff and i believe this to be questionable.

    With all due respect – the paleo cry “do not eat dairy” is highly suspect – while paleo’s generally have a pretty good f-off attitude towards conventional wisdom, they accept conventional anthropological assumptions that our paleo pals were not smart enough or capable enough to husband animals that provided milk/dairy nutritional adjunct… not right!- a close examination of the evidence leads to the conclusion that we very well could have and did keep at least goats – if not other mammals long into our paleo past enjoying the delectable white gold…

    Check out the argument here:
    http://daiasolgaia.com/?p=1302
    Ravi @ DaiaSolgaia.com

  16. Hi Ravi,

    Very interesting argument! I’m not sure about the precise dating but it is plausible that goat/sheep herding and dog domestication may have occurred much earlier than thought.

    Great series!

  17. Low Carb Age » Protein and the Low Carb Dieter - pingback on March 31, 2011 at 1:28 pm
  18. i guess protien in liquid form wont do much harm shakes or drinks like protica can be very helpful in preganancy specially in dehydration.

  19. Hi Jessica,

    Can’t one fix dehydration with water and electrolytes, and get protein from meat?

    I’m having trouble seeing a rationale for protein shakes.

    Best, Paul

  20. Love the blog, very good information here.

    About infants though, is their low protein intake not offset by the protein sparring effect of being in a hyper-caloric state combined with lots of sleep? Are there additionally other protein sparring properties of milk? it would be interesting to compare infant protein intake with adults adjusting for these factors and for weight/lean muscle mass.

  21. Hi Yves,

    Yes, excellent points. Babies have elevated calorie needs but not elevated protein needs.

    We tried to do such an adjustment in our book. Human breast milk is 40% carbs and the infant brain consumes 50% (if memory serves) of calories. For adults, we translate this to roughly a 20% carb optimum. Protein also scales up, from 7% in infant milk to 10-15% in adults.

    These are ballpark figures but I think they’re right.

  22. Hi Paul,

    Looking into what is the adequate amount of protein during pregnancy and I came across these studies, which warn against *too little* protein.

    One is quite recent. Have a look. I would appreciate any feedback!

    Thanks,
    Megan

    article: http://www.nutraingredients.com/Research/Maternal-malnutrition-may-mediate-metabolic-malady-Study

    the actual study: http://www.fasebj.org/content/early/2011/06/15/fj.11-181792.abstract

    another interesting study: http://ajpendo.physiology.org/content/298/2/E270.full

  23. Hi Megan,

    It’s well known that both too little and too much protein cause problems.

    I think the main issue with the mice studies is that the mice were not only fed diets relatively low in protein (10%), but the diets were calorie limited. So the pregnant mice could not eat more food. Protein deficiency is a strong driver of appetite, especially during pregnancy, so it’s likely that if the mice had been allowed to feed ad libitum there would have been no problems on a 10% protein chow.

    Human mothers are not prevented from eating, so I don’t think a protein deficiency is likely to occur.

    The key takeaway is that pregnant women should follow their food cravings and appetites, and not force themselves to eat very low protein.

    Best, Paul

  24. Hi Paul,

    Thank you abundantly for all the time and energy you put into changing people’s lives for the better!!!! We have tremendous appreciation for both you and your wife!

    My son was born IUGR. He’s 2 right now, and we’ve just recently discovered PHD, which we’re all following right now. I wonder if this diet will help reduce the risk for all the things that he’s at risk for. I’m sure I ate too much protein during the pregnancy ( I started eating Weston Price midway through my pregnancy) – that in addition to having been born IUGR, is he destined to have metabolic issues, no matter how we eat now?

    Thanks so much!
    Alex

    • Hi Alex,

      Out of interest, the cause of the IUGR may have been due to a bad placenta and not protein (did you go for the Nuchal Translucency test in the 1st trimester, which would have measured the PAPP-A in your blood – an indicator of how good the placenta is working). Low PAPP-A can be linked to IUGR. Hope your son is doing better now?

      I’m currently 16 weeks pregnant, with a very low PAPP-A (0.19MoM) and try and follow Weston Price diet (cod liver/bone stock/butter/coconut oil etc), with a main focus on vegetables and fruit, trying to avoid grains or eat sourdough bread and rice pasta instead.

      thanks
      Sonja

  25. Hi Alex,

    Welcome!

    The nutritional problems during pregnancy probably do have long-term effects, but they’re usually not effects that would prevent him from having a good healthy life.

    I don’t think he’s destined to have metabolic issues. Just as a comparison, I was a twin and my mother had cancer, and I think that led to my sister and I being malnourished in the womb. We both weighed under 5 pounds at birth. I’ve had health problems, but I would say that bad diet after birth and untreated infections, not pre-birth nutrition, are far and away the major factors in my own health problems.

    As you follow the diet, be aware that toddlers need a little more carbs than adults, more like 40% for him compared to 20% for you. In general, if you confine him to “real food” (ie, no sugar or vegetable oils) then you can let his taste preferences be your guide – let him choose how much of each food to eat, you guide him to eating healthy food.

    Best wishes and let me know how you do!

    Best, Paul

  26. Thank you SO SO MUCH for taking time to respond! I will definitely let you know how we do : ).

    I just wanted to share some information that you might find useful in terms of addressing infections. We’ve been working with Dr Larry Wilson, an MIT graduate,

    http://www.drlwilson.com/

    a Hair Mineral Analyst. He’s written a book, Sauna Therapy, where he discusses his personal experience using infrared saunas to help him both detox from heavy metals and balance out his mineral ratios.

    I think it’s something definitely worth checking out.

    Blessings and joy!
    Alex

  27. Do you have suggestions on how to calculate this without counting calories? Counting anything makes me nuts, but I want to be mindful of this. Also, I had gestational diabetes my last pregnancy and thankfully do not have it this pregnancy (I’m 26w), so I’ve been moderating my carbs. Should I just up fats and vegetables?

    • Hi heather,

      Go by taste. Let your food be tasty, that will help ensure meat isn’t too lean. Let your plant foods take up substantially more space on your plate than animal foods. Don’t force yourself to eat extra meat if you don’t feel like it. But eat enough protein – if you have an appetite for meat or fish, eat it.

  28. Thanks for the comment back! I’m eating lots of fat, so I think I’ll be OK. 🙂

  29. Hi Paul, Thanks so much to you and your wife for writing your book! I see it has been over a year since you have commented on this post, so I would not be surprised if you never responded, but I thought it might be worth a try!

    I am pregnant myself, 27 weeks and I am also a midwife and acupuncturist and I recommend this diet to everyone. My question is what should one do about timing of eating when pregnant? I see that you recommend spacing meals and not eating too often, but I find some weeks he has growth spurts and my hunger goes way up and I find myself eating 5 or 6 times a day, then other weeks I am satisfied with 3 meals a day. I imagine I will feel the same fluctuations when breastfeeding. Any advice? Is fewer larger meals out the window since weightloss is not something I am concerned about now? Also, I am feeling less and less space in my stomach, so eating large meals is harder!

    Thanks again,

    Jasmine

    • Hi Jasmine,

      The primary rule is that if you more than casually hungry, you should eat. The brain knows how what the body needs better than any outside person. It’s perfectly fine to eat 5-6 times a day one week and 3 times a day another.

      I would just do what seems most natural during pregnancy as far as meal size and frequency. Normally yes, fewer larger meals is better, but it doesn’t make a big difference.

  30. Okay, so strictly in the sense of pregnancy, less protein more fat? But in your case for weightloss you say less fat right? Do you by chance have percentile ratios for these? Like pregnancy 60% carbs 10% protein 20% fat? That sort of thing? Thanks Dr. J!

    • Hi Ashley,

      No, you want something more in accord with the food plate.

      If you’re not trying to lose weight: 35% carb 15% protein 50% fat.

      I would not recommend trying to lose weight during pregnancy, unless it happens naturally without hunger.

  31. Thanks for the reply! I wasn’t talking about losing weight during pregnancy although I can see how I wrote it that it appeared that way.

    I just was wondering the ratios for pregnancy, weight loss, and maintenance…separately…not together haha!

    So maintenance is 35% carb, 15% protein, and 50% fat. I’m guessing you drop the fat to something like 35% if you are trying to lose weight and use the maintenance ratios for pregnancy too? Thanks!

  32. YAY! I always felt guilty because I didn’t eat a ton of protein when pregnant and my son is always in the 5-10% for weight 🙁 He’s in the 70%+ for height. I did have a nearly perfect pregnancy though and he was born 1 hour before his due date vaginally.

    Question for you though… I read that the liver needs adequate protein to detoxify estrogen… like 80 grams + for women. Have you ever heard of this?

    Also, what are plant forms of protein? Chia seeds? Nuts? Soy? Just want to be sure I’m avoiding 🙂

    • Hi Eve,

      Adequate protein intake is important for detoxification. The liver is the first place protein is lost on a protein-deficient diet, and detoxification is the first liver function to be lost. This is true for all toxins, not just estrogen.

      80 grams is certainly enough protein for nearly all women assuming sufficient carbs are eaten.

      Plants are not a good source of protein. Beans are the most protein-rich plants, we recommend avoiding those. The bran of cereal grains also has a fair amount of protein (eg gluten).

  33. Would these same recommendations apply to a twin pregnancy? I read “When You’re Expecting Twins, Triplets, and Quads” by Barbara Luke and based on her research, she recommends a 3,500 kcal per day diet and 175g of protein. She claims that mothers who follow these guidelines and gain 28 pounds by 24 weeks are more likely to carry the twins to term and deliver normal weight babies (rather than underweight). What are your thoughts on this? Thank you!

  34. Hello, I have followed many different diets that range from the high-protein bodybuilding diet to the extreme raw vegan [high fruit/veg/low fat] diet… I am now pregnant. I have read a bunch of literature on appropriate levels of proteins, salts etc.and their importance during pregnancy: I find The Brewer’s Diet has many decent arguments as to why women need between 80-100g/Protein per day. I see you echoed this above saying that 80g is certainly sufficient. I am wondering what the ratio has to do with it? You say 10-20% protein is a good range for humans, including pregnant women. 80g is the low end of the daily allowance: for simplicity sake, lets say our goal is 15P:35C:50F with 80gP being the goal. That is approx 2133 cal/day at 320:747:1066 respectively. am i correct? I agree that a lower percentage protein diet is also wise, but can you explain to me WHY?. i followed 80:10:10 by Doug Graham for about a year, and thought it was great, however not sufficient for living pleasantly in society… and I certainly missed cheese! 🙂 Dr. Graham also makes the argument toward protein intake for adults being likely under 10% due to looking at what is in breast milk, however, he does not address the fact of Carbs and Fats being a much different percentage in breast milk than that of his High Fruit diet. Thanks! People seem to play around with different ratios of macronutrients for diets all the time, and that is a major difference between most all diets. I am wondering how/why you look at the ratios and deduce what is best. Maybe you answer this in some book? or it might be a longer discussion about your own process.

  35. Also, I am curious about what the macronutrient ratio of Chimp Milk is? I know the protein content is something like 1% more than that of humans. I think humans have the lowest concentration of protein in breast milk compared to all other animals. I am curious about comparing the nutrition of adult great apes in the wild vs. their breast milk content… and then using that as a basis on coming up with a diet ratio for adult humans. Is this something you might know about?

  36. Sorry for the onslaught of questions/comments, but this stuff really has me thinking. Have you ever tried any athletic performance on your diet? I would be curious to see how it works on an athlete, especially with the high ratio of fat. Fat tends to make me sleepy, and not perform athletic endeavors very well, and slow me down… whereas lowfat/high sugar [good sugar, from fruit] such as recommended in 80/10/10 seems more optimal. I admit I have not given a ‘clean’ high fat, low carb diet any consistent testing during my training to date. I can attest to a high protein, low fat, low carb diet making a human nearly braindead… and the need for performance enhancing supplements obvious in order to get through workouts. Thanks for all your dedication and hard work in the ever-confusing and convoluted field of nutrition… cheers.

  37. Do you know the macronutrient ratio in Chimp breast milk? I know they have slightly higher protein percentage than humans… such as 1% or so. Humans have the lowest percentage of protein in breast milk. I am wondering what your commentary is on the diet of wild adult chimpanzees vs. the nutrient make-up of chimp milk for thier babies… I would thinking looking at the great apes and studying what adults eat in the wild vs. the nutrient makeup of the breast milk would give us an indicator of what we humans should be eating as adult in comparison to our own breast milk make-up. And, I would be interested to know what wild pregnant chimps eat in comparison to non-pregnant chimps to see if they eat in order to have more caloric intake as well as protein. [not as much to change the ratio of their eating, but the volume of eating in order to get enough protein/calories for the placenta]. I also wonder if pregnant chimps eat more greens than other chimps in order to get a higher sodium intake? interesting stuff.

  38. Pregnancy and Food Aversions - pingback on January 17, 2014 at 4:02 pm
  39. This topic interests me. I do notice I crave more carbs in pregnancy. Now I know why. Can you tell me what a plate of food would look like for these recommended proportions eg. 1/4 plate of potatoes with butter, 1/4 plate steamed veg with butter and 1 chicken drumstick? Would that sort of ratio be OK?

  40. hi, i’m not sure how to work out how many grams of protein are 15% of calories. can anybody explain? thanks!

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  44. This is an old post, but I specifically searched for it bc I recalled reading it a few years ago. At the time I was not pregnant so it didn’t really resonate with me, but I am currently pregnant with twins. I have noticed that the twin mother to be mantra is “protein, water, protein, water”. It is as though those are the only important nutrients. The water makes sense as we are carrying so much extra blood, but the protein has never made a ton of sense to me. However, it seems that many mothers of twins, especially those that are afflicted with TTTS or IUGR are told to throw back the protein in massive quantities. I wonder why this would be?

  45. Low Protein Intake During Pregnancy - Healthy Pregnancy - pingback on September 26, 2015 at 5:57 pm

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