So far as I can tell, all the advice here is from metabolically privileged folks who don’t know they’re metabolically privileged and don’t comprehend the nothing fucking works phenomenon that obtains if you’re not metabolically privileged.
This is more of an anecdote than advice, but my wife has had some similar issues, i.e. being able to lose weight on occasion in some fashion, but then becoming immune to it and having it creep back on. Recently, she got some software that makes dietary recommendations based on genotype information—a combination of blood type, body proportions, PROP tasting ability, tooth shapes, etc. etc. (It took an hour or two to take all the measurements, tests, and observations required.)
The theory behind the software is that humans are evolved to thrive on different sorts of foods; even if you are going to eat “paleo”, your ancestral geography will make a difference as to which specific fruits, nuts, roots, eggs, and meats you’re going to thrive on. So, the software uses a bunch of known physical genetic markers (like torso length to leg length ratio, index/ring finger ratio, etc.) to identify a dietary genotype grouping.
From these measurements, the software spat out a list of foods to eat, avoid, or eat more of to lose weight… and many of the things to eat to lose weight were pretty obscure, while many of the things to avoid were things she ate a lot of. After cutting out all the things to avoid, her weight has started drifting down instead of up.
It’s still early days yet, in that one would expect this effect per Roberts’ hypothesis. However, one of the interesting things is that the foods the diet recommended just happened to also match things she’d been eating on previous diets when she lost weight… and many of the “avoid” items were things she’d been eating a lot of when struggling to stop gaining.
That is, if you looked at it in terms of “doing the X diet”, “doing the Y diet”, and so on, her results would appear more mixed than if you looked at the detail of, “doing the X diet eating food A” versus “doing the X diet eating food B.” For example, “doing Atkins eating beef and horseradish”, vs. “doing Atkins eating lots of whey protein bars and chicken.” The overall effectiveness of “Atkins” in general vs. the specific effectiveness of “beef and horseradish” are different, in other words, and the software’s recommendations seem to be similar to the more effective variations within specific diets she’s tried.
I haven’t done the full analysis on myself yet, but the preliminary food list from the author’s book seems similarly correlated with my own weight loss attempts.
I will mention more when I know more, but if you’re looking for something that specifically deals with uncommon metabolic challenges, you might find it worthwhile to investigate. Certain genotype classifications are supposed to be more weight-loss resistant than others—for example, my wife’s list has a LOT fewer “eat more of this to lose weight” items than mine does in most food categories, and in some categories she has none at all.
IOW, the author’s theoretical framework includes a basis for metabolic “privilege” and “challenge”, as well as extremely-specific recommendations to accomodate them. (So specific, its recommendations distinguish which species of mushrooms and which, out of dozens of different kinds of cheese you should or shouldn’t eat.)
This system would need to be based off an awful lot of data to be producing such specific prescriptions based on a wide range of minor differences. Data which as far as I know does not exist. It would be an excellent thing to be working towards but right now does not sound credible.
Are you sure about that? Wikipedia’s Nutrigenomics page seems to reference a lot of articles on documented gene-nutrition interactions, incuding the effects of nutrients on genetic expression.
This system would need to be based off an awful lot of data to be producing such specific prescriptions
I don’t think SWAMI actually needs that many pieces of data to make strong recommendations; it claims to be using only 225 of the nutrients or substances found in 800 foods as a basis for its suggestions.
As I understand it, it’s essentially doing something like, “people with this set of genes tend to have these problems; these nutrients tend to help with that kind of problem, these others make it worse—so rate the foods containing those nutrients up or down accordingly...” and then it computes a total score for each food, and uses various cutoff levels to rank the food as “good”, “bad”, or “meh”. ;-)
IOW, it’s not using a massive array of studies on individual foods’ effects, but rather, a scoring system based on known nutrient-genome-health correlations. And statistical prediction rules can easily outperfrom human experts, so it shouldn’t be especially surprising that you could get some pretty good results out of less than “an awful lot of data”.
It would be an excellent thing to be working towards but right now does not sound credible
On my epistemically rational side, I would certainly like to see more references myself. D’Adamo’s book and software describes many kinds of “this does this to that and is related to gene XYZ-123” things that cause my brain to go “[citation needed]”—i.e., I would really like to have a better idea of what his epistemology for all this stuff is, besides, “we studied it in my lab”.
On the other hand, my instrumentally rational side has been happy enough with the results from following the book’s recommendations so far, to be willing to buy the full kit. The interesting question will be whether I can lose more than the typical “20 pounds and then start regaining” that happens when people switch to new diets, and that will take a bit longer to determine.
(OTOH, I’m already about 20 pounds down from my last major dietary change about 8 months ago… so perhaps any further weight loss will be a good sign.)
Why do you believe that? I wouldn’t be surprised if there are nutrition scientist who have a much better model of nutrition that is publicly availabe, which we can’t find or notice because of all the noise in the field.
My knowledge of the field combined with the usual meta-information that I must always use to evaluate such possibilities.
Nothing in the description here gives any of the indications that it is the herald of hidden deep wisdom from the upper echelons of the nutrition sciences that is hidden from the rest of us. It is also too many steps beyond what the more mainstream (or even ‘mainstream contrarian’) scientists present to be at all likely.
This isn’t a nutritional scientist we are talking about here. It’s a naturopathic quack. The same guy who wrote the laughable “Eat Right For Your Blood Type”.
Ok, I just took a look at the sample result set that Eby linked to, and I, like you, am not impressed. This guy is so much a part of the noise, he isn’t even the noise that could be reasonably mistaken for a real expert.
So… here’s the thing. You and wedrifid are doing something that has me concerned.
Specifically, you’re putting me into a position where, for consistency, I feel compelled to argue a case for something that I myself don’t currently have a hugely high degree of confidence in… simply because you’re not actually providing in your arguments, any information which I could either specifically agree or disagree with.
IOW, comments like, “quack”, “laughable”, and “noise” do not give me any information about your epistemology, and therefore light up on my board “[citation needed]” just as much as it did for what I’ve been reading from D’Adamo.
So, it would be nice if you could identify specific concerns instead… who knows, I might agree with them!
OTOH, my consistent experience is that just because somebody has a stupid-sounding theory, doesn’t mean their advice doesn’t actually work. (Likewise, people who have good theories are often lousy at giving usable advice.)
Heck, take Seth Roberts as an example here: the entire idea of drinking oil or sugar water to lose weight is also “laughable”, “noise” and “quack”… and yet it still seems to work for plenty of people.
Heck, there are elements of Roberts’ theory that don’t make sense to me, from a “fewest elements to make the circuit” point of view. (For example, I don’t think “set point” is a real thing; I think it’s more likely an epiphenomenon of something else.)
But that doesn’t mean I wouldn’t recommend it… just that I’d avoid recommending it to people who jump to conclusions first and ask questions later. ;-)
Anyway… specifics, please. Otherwise, I’ll simply bow out of this discussion on the assumption that you don’t actually have any new evidence to present.
IOW, a knee-jerk dismissal on grounds of ridiculousness isn’t an independent data point for Bayesian analysis. Citing papers disproving D’Adamo’s hypotheses, on the other hand, would be quite welcome.
(I’ve actually googled around for criticisms of both his blood type and genotype work, and have yet to find a single cite that doesn’t have a more-recent countercite; the vast majority of criticism, however, appears to be of the, “that’s so silly I won’t even bother to argue the idea seriously” variety. Maybe this is evidence that he’s a quack, but at least his responses to the critiques include some citations in his favor.)
A big red flag is that where I expected to see an analysis of what mixture of the various ancestral types a person is, I see a declaration that the person fits into one of 6 little boxes. This despite the fact these types describe multiple features, controlled by different genes, in a sexually reproducing population that represents all types. Now, not all genes are selected for independantly, genes nearby on the same chromosone can be correletated. But a model of which dietary traits correspond to which easily measurable traits should be more complicated than assigning a cluster of dietary traits to a cluster of easily measured traits.
A big red flag is that where I expected to see an analysis of what mixture of the various ancestral types a person is, I see a declaration that the person fits into one of 6 little boxes.
FYI, my wife’s actual profile showed this; more precisely, IIRC it rated her as 44% Explorer, based on the traits given. It did not show what percentages the other 5 boxes broke down to, and I don’t know whether those factors were also taken into account in the analysis. (I also don’t know what precisely the percentage represents; i.e. is it a probability, a “percentage of your traits”...?)
The sample profile I linked appears to date from 2008; so perhaps the percentage report was added to the software later. But in both cases, if I understand correctly, the software simply presents the highest-scoring of the six boxes, rather than saying, “this is you”.
Still, compared to most ways of nutritionally grouping people, six is actually a LOT of boxes.
But a model of which dietary traits correspond to which easily measurable traits should be more complicated than assigning a cluster of dietary traits to a cluster of easily measured traits.
From what I read in his book, he describes the types in terms of basic strategies for responding to the environment, where there are only a few good choices to make. IOW, the stereotypes are supposed to represent stable strategies for responding to infections, shortages, and other stressors. That is, there are not an unlimited number of ways to do things in those areas, so you end up with large clusters.
I have not studied this in any detail, mind you; I confess my primary interest in the book was more to look at the food lists for my type, to compare against my personal dietary history.
As I said, I’m less interested in the plausibility or sensibility of a theory per se, than with the correlation of its advice with the obtaining of results… especially results for myself in particular. (And I remain cautiously optimistic on that front where his advice is concerned.)
FYI, my wife’s actual profile showed this; more precisely, IIRC it rated her as 44% Explorer, based on the traits given. It did not show what percentages the other 5 boxes broke down to, and I don’t know whether those factors were also taken into account in the analysis. (I also don’t know what precisely the percentage represents; i.e. is it a probability, a “percentage of your traits”...?)
Better, but still not good enough. If it is a mixture, what about the other 56%? Which 44% of the explorer traits? If it is a confidence level, the model doesn’t seem to rate itself very highly, so why should I be impressed with it?
From what I read in his book, he describes the types in terms of basic strategies for responding to the environment, where there are only a few good choices to make. IOW, the stereotypes are supposed to represent stable strategies for responding to infections, shortages, and other stressors. That is, there are not an unlimited number of ways to do things in those areas, so you end up with large clusters.
Suppose there are 2 stable strategies that each say how to deal with several specific problems, such that either of the 2 strategies work but a mixture somehow fails. These strategies, being complicated, are coded for by multiple genes. Suppose a man with one strategy and a women with the other strategy mate and have offspring. Those offspring are going to inherit some mixture of the two strategies, even discounting complications such as being heterzygous where the parents are homozygous, and therefore will employ an unfavorable mixture. You can not have multiple non mixable complicated traits in a sexually reproducing population, without tricks like having each member have the complete code for all possible traits, and a varying gene that switches on one of them, which we observe in sexual dimorphism at not much otherwise. Eliezer has written of this.
You can not have multiple non mixable complicated traits in a sexually reproducing population, without tricks like having each member have the complete code for all possible traits, and a varying gene that switches on one of them, which we observe in sexual dimorphism at not much otherwise.
But we do observe epigenetic traits—variations in gene expression based on environmental conditions, such as genes that act differently depending on how much exercise you get, or the level of testosterone in the fetal environment, or various other things.. D’Adamo’s claim here is that his typing groups are a combination of gene inheritance and gene expression, and his notion of “strategies” isn’t really the same as say, having a completely different way of digesting foods.
It’s more like identifying which places to store fat in first—something that (IIUC) we already know is heritable. The fact that fat gets stored isn’t changed, just how much, where, and how quickly. Something like that can make a big difference on a practical level to a person’s life, without being a particularly complex adaptation in itself.
For those who have an interest in the possible benefits of a blood type diet the wikipedia page is, as is often the case, a good place to get the basics. Particularly by following up on the references cited.
I personally am not going to investigate further, the mainstream position seems to be solid:
Nevertheless, the consensus among dieticians, physicians, and scientists is that the theory is unsupported by scientific evidence.[1][2][3][4][5][6][7]
Nevertheless, the consensus among dieticians, physicians, and scientists is that the theory is unsupported by scientific evidence.[1][2][3][4][5][6][7]
AFAICT, not one of those seven references involves a journal citation at all; they are all either “we don’t think this is credible”, or “we need more evidence”. (The seventh is a (valid, IMO) critique of D’Adamo’s epistemology.)
I notice, however, that your quotation from the Wikipedia page is from a less-informative part of the page, than say, this one:
D’Adamo’s Blood Type Diet has met with criticisms for many different reasons,[1][2][3][4][5][6][7] some of which have been addressed publicly by D’Adamo.[9]
And D’Adamo actually provides journal citations backing many of his responses. The strongest argument against him is, “not a lot of clinical evidence”, which is quite a bit different than “shown false”. (And a critique that could be equally levelled at Seth Roberts.)
Except for the (IMO valid) epistemological critique, the seven “against” references rely on either simple dismissal or attempts to refute points that D’Adamo actually has cites in his favor for.
IOW, you’re not providing any new useful information here.
Since there seems to be a persistant effect of people losing weight when they start a diet and then regaining it presumably because their digestive system learns that the food has calories and makes them crave it more, I wonder what would happen if someone changed diets everytime right after the initial weight loss from their previous diet. I have mostly only heard about this effect, so I am not sure what the timescale of each diet should be. Also, I wonder how much long term memory the digestive system has, presumably a suitably large rotation would work. (And have we historically, before advances in agriculture, been forced to do this somewhat by food going in and out of season?)
This software sounds interesting. Can you provide more information on it? Can one use it alone at home or does it require fancier tests that one would involve doctors to handle?
This software sounds interesting. Can you provide more information on it?
It’s called SWAMI Xpress—don’t ask me what the letters stand for. (It’s actually web-based; what you’re buying is a passcode that’s physically shipped to you.)
Edit to add: here’s a sample diet report (PDF) from the software, in case you’re wondering what its output looks like.
Can one use it alone at home or does it require fancier tests that one would involve doctors to handle?
ABO blood type and secreter status are the only tests that have to be sent off for lab work; the rest can be done entirely at home if you have someone to help with the measurements and observations. (For example, the PROP test is a blinded taste test, so it’s easier if somebody else administers it; other tests require inspecting the shape of your teeth, measuring the angle of your jaw, etc., which are very difficult to do by yourself.)
My wife already knew her ABO/secretor results, but she bought the home genotyping kit to get the PROP test strips and fingerprinting kit. There’s enough stuff in the kit to do at least two people—it comes with a lot of taste strips, and a bunch of the stuff (like the jaw-measuring protractor) can be reused for as many people as you like.
The book has some shortcuts you can do for a quicker but lower-accuracy grouping, using a smaller set of measurements; the software is supposed to basically take more factors into account in food selection than what can be done with the six generic charts in the book.
(As I understand it, a person can have markers from more than one group, so a weighted scoring system is used to rate the markers.)
This is more of an anecdote than advice, but my wife has had some similar issues, i.e. being able to lose weight on occasion in some fashion, but then becoming immune to it and having it creep back on. Recently, she got some software that makes dietary recommendations based on genotype information—a combination of blood type, body proportions, PROP tasting ability, tooth shapes, etc. etc. (It took an hour or two to take all the measurements, tests, and observations required.)
The theory behind the software is that humans are evolved to thrive on different sorts of foods; even if you are going to eat “paleo”, your ancestral geography will make a difference as to which specific fruits, nuts, roots, eggs, and meats you’re going to thrive on. So, the software uses a bunch of known physical genetic markers (like torso length to leg length ratio, index/ring finger ratio, etc.) to identify a dietary genotype grouping.
From these measurements, the software spat out a list of foods to eat, avoid, or eat more of to lose weight… and many of the things to eat to lose weight were pretty obscure, while many of the things to avoid were things she ate a lot of. After cutting out all the things to avoid, her weight has started drifting down instead of up.
It’s still early days yet, in that one would expect this effect per Roberts’ hypothesis. However, one of the interesting things is that the foods the diet recommended just happened to also match things she’d been eating on previous diets when she lost weight… and many of the “avoid” items were things she’d been eating a lot of when struggling to stop gaining.
That is, if you looked at it in terms of “doing the X diet”, “doing the Y diet”, and so on, her results would appear more mixed than if you looked at the detail of, “doing the X diet eating food A” versus “doing the X diet eating food B.” For example, “doing Atkins eating beef and horseradish”, vs. “doing Atkins eating lots of whey protein bars and chicken.” The overall effectiveness of “Atkins” in general vs. the specific effectiveness of “beef and horseradish” are different, in other words, and the software’s recommendations seem to be similar to the more effective variations within specific diets she’s tried.
I haven’t done the full analysis on myself yet, but the preliminary food list from the author’s book seems similarly correlated with my own weight loss attempts.
I will mention more when I know more, but if you’re looking for something that specifically deals with uncommon metabolic challenges, you might find it worthwhile to investigate. Certain genotype classifications are supposed to be more weight-loss resistant than others—for example, my wife’s list has a LOT fewer “eat more of this to lose weight” items than mine does in most food categories, and in some categories she has none at all.
IOW, the author’s theoretical framework includes a basis for metabolic “privilege” and “challenge”, as well as extremely-specific recommendations to accomodate them. (So specific, its recommendations distinguish which species of mushrooms and which, out of dozens of different kinds of cheese you should or shouldn’t eat.)
This system would need to be based off an awful lot of data to be producing such specific prescriptions based on a wide range of minor differences. Data which as far as I know does not exist. It would be an excellent thing to be working towards but right now does not sound credible.
Are you sure about that? Wikipedia’s Nutrigenomics page seems to reference a lot of articles on documented gene-nutrition interactions, incuding the effects of nutrients on genetic expression.
I don’t think SWAMI actually needs that many pieces of data to make strong recommendations; it claims to be using only 225 of the nutrients or substances found in 800 foods as a basis for its suggestions.
As I understand it, it’s essentially doing something like, “people with this set of genes tend to have these problems; these nutrients tend to help with that kind of problem, these others make it worse—so rate the foods containing those nutrients up or down accordingly...” and then it computes a total score for each food, and uses various cutoff levels to rank the food as “good”, “bad”, or “meh”. ;-)
IOW, it’s not using a massive array of studies on individual foods’ effects, but rather, a scoring system based on known nutrient-genome-health correlations. And statistical prediction rules can easily outperfrom human experts, so it shouldn’t be especially surprising that you could get some pretty good results out of less than “an awful lot of data”.
On my epistemically rational side, I would certainly like to see more references myself. D’Adamo’s book and software describes many kinds of “this does this to that and is related to gene XYZ-123” things that cause my brain to go “[citation needed]”—i.e., I would really like to have a better idea of what his epistemology for all this stuff is, besides, “we studied it in my lab”.
On the other hand, my instrumentally rational side has been happy enough with the results from following the book’s recommendations so far, to be willing to buy the full kit. The interesting question will be whether I can lose more than the typical “20 pounds and then start regaining” that happens when people switch to new diets, and that will take a bit longer to determine.
(OTOH, I’m already about 20 pounds down from my last major dietary change about 8 months ago… so perhaps any further weight loss will be a good sign.)
Why do you believe that? I wouldn’t be surprised if there are nutrition scientist who have a much better model of nutrition that is publicly availabe, which we can’t find or notice because of all the noise in the field.
My knowledge of the field combined with the usual meta-information that I must always use to evaluate such possibilities.
Nothing in the description here gives any of the indications that it is the herald of hidden deep wisdom from the upper echelons of the nutrition sciences that is hidden from the rest of us. It is also too many steps beyond what the more mainstream (or even ‘mainstream contrarian’) scientists present to be at all likely.
This isn’t a nutritional scientist we are talking about here. It’s a naturopathic quack. The same guy who wrote the laughable “Eat Right For Your Blood Type”.
Ok, I just took a look at the sample result set that Eby linked to, and I, like you, am not impressed. This guy is so much a part of the noise, he isn’t even the noise that could be reasonably mistaken for a real expert.
So… here’s the thing. You and wedrifid are doing something that has me concerned.
Specifically, you’re putting me into a position where, for consistency, I feel compelled to argue a case for something that I myself don’t currently have a hugely high degree of confidence in… simply because you’re not actually providing in your arguments, any information which I could either specifically agree or disagree with.
IOW, comments like, “quack”, “laughable”, and “noise” do not give me any information about your epistemology, and therefore light up on my board “[citation needed]” just as much as it did for what I’ve been reading from D’Adamo.
So, it would be nice if you could identify specific concerns instead… who knows, I might agree with them!
OTOH, my consistent experience is that just because somebody has a stupid-sounding theory, doesn’t mean their advice doesn’t actually work. (Likewise, people who have good theories are often lousy at giving usable advice.)
Heck, take Seth Roberts as an example here: the entire idea of drinking oil or sugar water to lose weight is also “laughable”, “noise” and “quack”… and yet it still seems to work for plenty of people.
Heck, there are elements of Roberts’ theory that don’t make sense to me, from a “fewest elements to make the circuit” point of view. (For example, I don’t think “set point” is a real thing; I think it’s more likely an epiphenomenon of something else.)
But that doesn’t mean I wouldn’t recommend it… just that I’d avoid recommending it to people who jump to conclusions first and ask questions later. ;-)
Anyway… specifics, please. Otherwise, I’ll simply bow out of this discussion on the assumption that you don’t actually have any new evidence to present.
IOW, a knee-jerk dismissal on grounds of ridiculousness isn’t an independent data point for Bayesian analysis. Citing papers disproving D’Adamo’s hypotheses, on the other hand, would be quite welcome.
(I’ve actually googled around for criticisms of both his blood type and genotype work, and have yet to find a single cite that doesn’t have a more-recent countercite; the vast majority of criticism, however, appears to be of the, “that’s so silly I won’t even bother to argue the idea seriously” variety. Maybe this is evidence that he’s a quack, but at least his responses to the critiques include some citations in his favor.)
A big red flag is that where I expected to see an analysis of what mixture of the various ancestral types a person is, I see a declaration that the person fits into one of 6 little boxes. This despite the fact these types describe multiple features, controlled by different genes, in a sexually reproducing population that represents all types. Now, not all genes are selected for independantly, genes nearby on the same chromosone can be correletated. But a model of which dietary traits correspond to which easily measurable traits should be more complicated than assigning a cluster of dietary traits to a cluster of easily measured traits.
FYI, my wife’s actual profile showed this; more precisely, IIRC it rated her as 44% Explorer, based on the traits given. It did not show what percentages the other 5 boxes broke down to, and I don’t know whether those factors were also taken into account in the analysis. (I also don’t know what precisely the percentage represents; i.e. is it a probability, a “percentage of your traits”...?)
The sample profile I linked appears to date from 2008; so perhaps the percentage report was added to the software later. But in both cases, if I understand correctly, the software simply presents the highest-scoring of the six boxes, rather than saying, “this is you”.
Still, compared to most ways of nutritionally grouping people, six is actually a LOT of boxes.
From what I read in his book, he describes the types in terms of basic strategies for responding to the environment, where there are only a few good choices to make. IOW, the stereotypes are supposed to represent stable strategies for responding to infections, shortages, and other stressors. That is, there are not an unlimited number of ways to do things in those areas, so you end up with large clusters.
I have not studied this in any detail, mind you; I confess my primary interest in the book was more to look at the food lists for my type, to compare against my personal dietary history.
As I said, I’m less interested in the plausibility or sensibility of a theory per se, than with the correlation of its advice with the obtaining of results… especially results for myself in particular. (And I remain cautiously optimistic on that front where his advice is concerned.)
Better, but still not good enough. If it is a mixture, what about the other 56%? Which 44% of the explorer traits? If it is a confidence level, the model doesn’t seem to rate itself very highly, so why should I be impressed with it?
Suppose there are 2 stable strategies that each say how to deal with several specific problems, such that either of the 2 strategies work but a mixture somehow fails. These strategies, being complicated, are coded for by multiple genes. Suppose a man with one strategy and a women with the other strategy mate and have offspring. Those offspring are going to inherit some mixture of the two strategies, even discounting complications such as being heterzygous where the parents are homozygous, and therefore will employ an unfavorable mixture. You can not have multiple non mixable complicated traits in a sexually reproducing population, without tricks like having each member have the complete code for all possible traits, and a varying gene that switches on one of them, which we observe in sexual dimorphism at not much otherwise. Eliezer has written of this.
But we do observe epigenetic traits—variations in gene expression based on environmental conditions, such as genes that act differently depending on how much exercise you get, or the level of testosterone in the fetal environment, or various other things.. D’Adamo’s claim here is that his typing groups are a combination of gene inheritance and gene expression, and his notion of “strategies” isn’t really the same as say, having a completely different way of digesting foods.
It’s more like identifying which places to store fat in first—something that (IIUC) we already know is heritable. The fact that fat gets stored isn’t changed, just how much, where, and how quickly. Something like that can make a big difference on a practical level to a person’s life, without being a particularly complex adaptation in itself.
I don’t think that this evidence means what you think it means.
For those who have an interest in the possible benefits of a blood type diet the wikipedia page is, as is often the case, a good place to get the basics. Particularly by following up on the references cited.
I personally am not going to investigate further, the mainstream position seems to be solid:
I’m going with that.
AFAICT, not one of those seven references involves a journal citation at all; they are all either “we don’t think this is credible”, or “we need more evidence”. (The seventh is a (valid, IMO) critique of D’Adamo’s epistemology.)
I notice, however, that your quotation from the Wikipedia page is from a less-informative part of the page, than say, this one:
And D’Adamo actually provides journal citations backing many of his responses. The strongest argument against him is, “not a lot of clinical evidence”, which is quite a bit different than “shown false”. (And a critique that could be equally levelled at Seth Roberts.)
Except for the (IMO valid) epistemological critique, the seven “against” references rely on either simple dismissal or attempts to refute points that D’Adamo actually has cites in his favor for.
IOW, you’re not providing any new useful information here.
I have stated my decision to defer to mainstream consensus in the face of, basically, very little that would leave me to doubt it.
Since there seems to be a persistant effect of people losing weight when they start a diet and then regaining it presumably because their digestive system learns that the food has calories and makes them crave it more, I wonder what would happen if someone changed diets everytime right after the initial weight loss from their previous diet. I have mostly only heard about this effect, so I am not sure what the timescale of each diet should be. Also, I wonder how much long term memory the digestive system has, presumably a suitably large rotation would work. (And have we historically, before advances in agriculture, been forced to do this somewhat by food going in and out of season?)
This software sounds interesting. Can you provide more information on it? Can one use it alone at home or does it require fancier tests that one would involve doctors to handle?
It’s called SWAMI Xpress—don’t ask me what the letters stand for. (It’s actually web-based; what you’re buying is a passcode that’s physically shipped to you.)
Edit to add: here’s a sample diet report (PDF) from the software, in case you’re wondering what its output looks like.
ABO blood type and secreter status are the only tests that have to be sent off for lab work; the rest can be done entirely at home if you have someone to help with the measurements and observations. (For example, the PROP test is a blinded taste test, so it’s easier if somebody else administers it; other tests require inspecting the shape of your teeth, measuring the angle of your jaw, etc., which are very difficult to do by yourself.)
My wife already knew her ABO/secretor results, but she bought the home genotyping kit to get the PROP test strips and fingerprinting kit. There’s enough stuff in the kit to do at least two people—it comes with a lot of taste strips, and a bunch of the stuff (like the jaw-measuring protractor) can be reused for as many people as you like.
The book has some shortcuts you can do for a quicker but lower-accuracy grouping, using a smaller set of measurements; the software is supposed to basically take more factors into account in food selection than what can be done with the six generic charts in the book.
(As I understand it, a person can have markers from more than one group, so a weighted scoring system is used to rate the markers.)