Changes to the Diet Doctor soy policy

We recently made some changes to our position on soy in our food policy. We’d like to explain those changes and clarify why we made them.
Previously, we recommended that soy should be limited due to uncertainties about its effects on health. This was based on animal and test-tube studies (very weak evidence) suggesting potential harm. However, after doing a thorough review of the most recent and highest-quality human research, it seems that for most people, soy has neutral — and in some cases possibly beneficial — health effects (references here). One caveat is that people with hypothyroidism may need closer monitoring if they eat soy regularly.
At Diet Doctor, our mission is to empower people everywhere to dramatically improve their health, by making low carb simple. To this end, we base our positions on controversial issues on the strongest, most rigorous research available. We know our members and readers depend on us to provide trustworthy, reliable information, and we always strive to do this.
We want to provide nutritious, low-carb protein options not only for omnivores, but also for vegetarians and vegans. Getting enough high-quality protein can be a challenge for vegans, perhaps especially on a low-carb diet.
Soy is a versatile and widely available source of plant protein that we’ve recently started including in some of our vegan and vegetarian recipes. Similar to our recommendations for animal products, we advise choosing less processed or fermented forms of soy, such as edamame, tofu, tempeh, and natto.
Some people have raised concerns that many soy products in the US may contain residues of glyphosate (Roundup), a controversial herbicide used on soy and other crops that requires further study.1 Fortunately, organic and non-GMO soy products contain no glyphosate.2 If you want to eat soy while avoiding glyphosate, choose tofu, tempeh, and natto labeled “non-GMO.”
It may be that you do not want to consume soy at all, and we completely understand this. Our vegan low-carb recipes that include soy are only provided as an option, and if you’re not a vegan there are many other options to get high-quality protein.
We hope you understand why we felt it was important to update our policy on this topic, to make sure we’re evidence based, and to make low carb simple for everyone who could benefit.
Thank you very much for continuing to trust Diet Doctor and for supporting our mission.


The Diet Doctor food policy
Here you can read our thoughts on different types of food and why we use or don’t use them in our low-carb and keto recipes.
Archives of Toxicology 2017: Glyphosate toxicity and carcinogenicity: a review of the scientific basis of the European Union assessment and its differences with IARC [expert review; ungraded] ↩
After testing 31 batches of soybeans, researchers found that unlike genetically-modified soybeans, conventional and organic soybeans contained no glyphosate:
Food Chemistry 2014: Compositional differences in soybeans on the market: Glyphosate accumulates in Roundup Ready GM soybeans [mechanistic study; ungraded] ↩
96 comments
The prairie fields of soy are responsible for great ecological damage and the destruction of much wildlife. They are heavily sprayed and require excessive amounts of water. Those who consume the much-touted plant based diet will kill the pollinators, turn healthy grazing land into desert and speed the destruction of the planet.
We include in our food policy that people with thyroid issues might want to avoid soy. It certainly is a personal choice. As someone with an underactive thyroid who eats a wide variety of animal protein, I'm unlikely to include soy in my diet as well. It's still nice to know that it's a good option for those who are primarily eating a plant-based diet.
(Oh, and the vegans probably won’t take over the world 😉, but if they do, it will be ok.)
I don’t know how much study has been done since, but I personally minimize soy as much as I can.
While it may be possible to find organic non -GMO soy and do extensive processing to reduce the negative effects, it is till a poor choice.
I now limit soy and them only use properly fermented and organic options.
From everything I have read, I will always use soy with caution.
Soybean oil is still not a good option. You can read more about it here,
https://www.dietdoctor.com/low-carb/fat#type-fat-avoid
Congratulations on your defeat of cancer!
May I ask what type of cancer you are concerned about?
Because Asian cultures have been eating soy for centuries as fermented side dishes to meat protein (but not in same manner as consumed today), doesn’t mean that it is healthy for those of European descent or African descent, etc. who for centuries did not eat soybeans, to eat a slab of tofu for dinner. It is a modern phenomena— too modern for evolutionary adaptation to have occurred. We are not insects.
The problem of contamination by GMO soy is a very real one — over 90% of soy grown in US is GMO. Unfortunately, NonGMO testing is riddled with holes. every soybean from an organic crop cannot be tested. If only one percent of soy certified slips through, who is to say you are not eating that one percent.
As we've said, most people on keto and low-carb diets get all the protein they need from animal sources. Our soy recommendations are mainly for vegans and vegetarians who want to follow a carb-restricted diet that provides adequate high-quality protein with very few carbs. Eating minimally processed soy a few times a week can help this group meet their essential protein needs.
Asparagus, pinto beans ,chickpeas, fava beans, pistachios, peanuts, and other fruits and nuts are also a major source of polyphenol.
It is not clear what exact effect isoflavones have on different types of cancers and some diseases. One thing is certain: Asian women and men have much lower rates of breast and prostate cancer if they consume isoflavones from an early age.
People who develop breast cancer need to find out FIRST whether it is estrogen receptor (ER) dependent, or ER-independent signaling mechanisms.
Asians also have much lower rates of baldness than the rest of the world. I often wonder why...
DietDoctor links to Peter's blog. Here's
what he has to say about soy:
https://high-fat-nutrition.blogspot.com/2019/08/who-gave-you-pancreat...
You might want to re-think this issue.
Respect has nothing to do with this. If you really want to respect someone's choice not to eat animals then that's fine but don't pretend veganism is healthy and make vegan how-tos to add to this craze. Be honest and truthful. Animal cruelty is the only reason for veganism I can't argue with.
Leaving aside the cringe-worthy trendiness of a 'Buddha bowl' (shouldn't it be full of yak butter anyway?) I am sorry to say that I agree with those who say that it appears that the DD team is jumping on the vegan bandwagon. I respect that DD wants to make the low-carbohydrate diet possible for everyone but I think that your previous line that vegetarian LCHF can work but that vegan diets are not recommended for optimum health was more honest and accurate. Don't you listen to your expert ex-veggie colleagues such as Zoe Harcombe?
I was a vegetarian for over 40 years and I attempted to be vegan for about 10 of them. After about 5 years, I became very unwell indeed and discovered that, in common with > 5% of the human population, I had an intolerance to soya. I immediately cut it out of my diet and recovered quickly but my attempts to remain vegan without soya resulted in my rapidly becoming very overweight. At my heaviest I weighed 97 kilos and I felt terrible - always hungry and tired. In short I was commiting 'carbicide' but I didn't know that at the time.
My saviour was the 5:2 diet which resulted in dramatic weight-loss. I then realised that carbohydrate meals with carbohydrate on the side were doing me no favours and I finally discovered Diet Doctor. I have never looked back.
I am now a very happy, fit 66-year-old omnivore with no weight issues. I have more energy now than I had in my 40s and 50s.
I understand about meat-eating and climate change and mass-produced, imported meat is certainly a disaster but otherwise this is not a black-and-white issue. A vegan diet which relies heavily on imported soya and fashionable but unethical products such as cashews is not the answer to climate change or anything else. I live in the Pennines and the only crop grown here is grass so eating locally-reared lamb makes sense on any level.
I wish good fortune to those who expect to thrive on a vegan diet (low carbohydrate, food-miles-friendly and ethical, of course!) They will certainly need it.
Someone commenting above wrote "I gave my son soy milk to try and help his eczema, before I knew more about nutrition. After just 1 week, his behaviour changed so dramatically for the worst, we feared he was autistic! Back to dairy and back to his normal self."
In animal studies soy isoflavones, in levels found in human diets, cause anxiety and social withdrawal in young female rats, altering sex-specific behaviours.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4996731/
https://academic.oup.com/toxsci/article/55/2/311/1735917
https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-...
https://www.ncbi.nlm.nih.gov/pubmed/11836067
Children of human mothers exposed to soy isoflavones in pregnancy have a doubled risk of early substance misuse, consistent with increased anxiety and dysphoria. It certainly seems as if soy can steal your childhood.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5659906/
Further, most human soy testing is of short duration. But the estrogenic effect builds up over 48 weeks to 80% of that of estradiol.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4386944/
Soy isoflavones are an over-the-counter medicine for women of a certain age - don't allow them to be fed to young people.
https://www.google.com/amp/s/amp.cnn.com/cnn/2017/03/07/health/soy-fo...
However, soy isoflavone levels in Asian diets are estimated to be only 10-15% of the levels that can be reached when a Western diet is based on soy meat substitutes, as these chemicals are concentrated in the protein fraction. We should also assume that there is some adaptation to a toxin in a population exposed to it for millennia, especially if that toxin can affect reproductive health.
The table in this paper illustrates the difference:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3074428/
Thank you for the update and for putting our minds at ease!
Tofu absorbs the flavor of the meat / seafood and expands the protein content of the dish at a lower cost.
I am considering trying carnivore diet, I was diagnosed with FAP age 39 (I'm 54 now) had a total colectomy in 2002 & I have a jpouch. I also suffer with IBS. I have been keto 2 yrs last June & love this WOE. I do still feel that veg & salads give me grief, hence my interest in carnivore. If you have any advice on how to get started, it would be most appreciated.
Lyndy
That's certainly personal preference, but it shouldn't cause any issues if you want to have both.
Circumstantial evidence sir.