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Cake day: June 1st, 2023

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  • So I say “consider how some people actually do have a single source of protein per day, they’re not combining it with other food sources, but they should be aware of this” and your reply is “oh but you see they’re combining it with other food sources so that’s not important” flawless logic.

    My point is that it effectively happens anyway without even having to think about it in 99% of cases. It’s not really a large issue in the slightest. It just makes things sound scarier and more complex than it needs to be. People have finite ability to focus on various health things, and this just isn’t something 99% of people need to be worried about

    If someone is eating the exact identical source exclusively, every single day with no variation in anything, they are likely going to end up deficient in other things way before this, regardless of which thing they are eating (unless it’s something like Huel or Soylent which is designed to include everything). This is not at the level of “someone has beans a lot”. This is at the level of “virtually all of your calories come from beans” to be some larger issue

    Many people use it as a lever to attack plant-based diets in situation that it just doesn’t apply at all by making it sound like it’s something you’re needing some spreadsheet for. It’s really not the case. Plus things like soy, chia, hemp, and more are also already complete too


    I never said that. You mentioned it, I said I agreed, and you mentioned it again to reinforce a point I never made. Trying to pad out the comment or something?

    I was not saying that you said this. I should have worded that better. I was trying to add some more context for relevant statements from authors talking about both complete proteins and protein combining. I did a poor job of that though


    because your body will absolutely not fully digest the 2g of protein in your 100g plate of white rice.

    You don’t need to digest all of it, it’s just about a specific amino acid (Methionine in this case which beans already have some of). It’s just a little bit to make it complete. For instance, one of the studies you linked with rice + lentils found the two together rose the DIASS to overall be 100% (122% for infants and kids, 143% for older adults)


    I should also note protein quality metrics are also often based on some faulty assumptions for plants in particular. For instance, the DIASS has some flaws that make it undervalue the quality of plant proteins

    While multiple strengths characterize the DIAAS, substantial limitations remain, many of which are accentuated in the context of a plant-based dietary pattern. Some of these limitations include a failure to translate differences in nitrogen-to-protein conversion factors between plant- and animal-based foods, limited representation of commonly consumed plant-based foods within the scoring framework, inadequate recognition of the increased digestibility of commonly consumed heat-treated and processed plant-based foods, its formulation centered on fast-growing animal models rather than humans, and a focus on individual isolated foods vs the food matrix. The DIAAS is also increasingly being used out of context where its application could produce erroneous results such as exercise settings. When investigating protein quality, particularly in a plant-based dietary context, the DIAAS should ideally be avoided.

    https://link.springer.com/content/pdf/10.1007/s13668-020-00348-8.pdf


  • Many researchers argue the exact opposite - that it is way overemphasized. Especially because thing you might not think of as protein sources can add the missing other amino acids. Things like wheat, rice, etc. also have protein that can complement others. It’s extremely unlikely for a bean heavy diet to actually have beans as the sole source of all protein even if is the main source

    Combining does not need to happen for every single meal: so long as the diet is varied and meets caloric needs, even vegans and vegetarians – people who tend to have more “incomplete protein” in their diet – can easily meet their amino acid needs. In other words, most people do not need to consider the completeness of proteins of single foods.[9]

    https://en.wikipedia.org/wiki/Complete_protein

    Especially the false idea that it has to be done at each meal

    Protein combining has drawn criticism as an unnecessary complicating factor in nutrition.

    In 1981, Frances Moore Lappé changed her position on protein combining from a decade prior in a revised edition of Diet for a Small Planet in which she wrote:

    "In 1971 I stressed protein complementarity because I assumed that the only way to get enough protein … was to create a protein as usable by the body as animal protein. In combating the myth that meat is the only way to get high-quality protein, I reinforced another myth. I gave the impression that in order to get enough protein without meat, considerable care was needed in choosing foods. Actually, it is much easier than I thought.

    “With three important exceptions, there is little danger of protein deficiency in a plant food diet. The exceptions are diets very heavily dependent on [1] fruit or on [2] some tubers, such as sweet potatoes or cassava, or on [3] junk food (refined flours, sugars, and fat). Fortunately, relatively few people in the world try to survive on diets in which these foods are virtually the sole source of calories. In all other diets, if people are getting enough calories, they are virtually certain of getting enough protein.”[13]: 162

    The American Dietetic Association reversed itself in its 1988 position paper on vegetarianism. Suzanne Havala, the primary author of the paper, recalls the research process:

    There was no basis for [protein combining] that I could see… I began calling around and talking to people and asking them what the justification was for saying that you had to complement proteins, and there was none. And what I got instead was some interesting insight from people who were knowledgeable and actually felt that there was probably no need to complement proteins. So we went ahead and made that change in the paper. [Note: The paper was approved by peer review and by a delegation vote before becoming official.]

    https://en.wikipedia.org/wiki/Protein_combining#Criticism


  • Focusing on complete proteins is largely unhelpful 99.9% of cases. Unless you are eating a exclusively singular source of protein for all meals and snacks it’s going to be not practically relevant. You don’t need to get all the amino acids at the same meal - just at some point in the day. And even thing you don’t think of as protein sources can be enough to make something complete. For instance, just adding rice is enough to make beans complete

    It’s also not the case that the beans don’t have all the amino acids, they do, it’s just less on certain ones. Which is why it can often take so little to make something complete protein. Complete is just a bar of “does it have this specific threshold of the amino acids”, not does it contain them at all















  • No, it doesn’t tell us nothing. These kinds of limitations are not uncommon for nutrition studies. It just is weaker evidence that doesn’t tell everything we ever might want. Studies will always have some methodological limitations. There is always some factor you might be forgetting or could do better. Science doesn’t work by looking at induvidial studies alone. We take things in aggregate

    That being said, of course things like RCTs will always be preferred and considered much stronger evidence. On that front, there have been some RCTs in other related health risk incidents with similar findings. For instance, I have read about some RCT studies for cardiovascular health. One meat industry funded review of RCT studies on cardiovascular risk for red meat found plant substitution improved predictors of cardiovascular health

    Substituting red meat with high-quality plant protein sources, but not with fish or low-quality carbohydrates, leads to more favorable changes in blood lipids and lipoproteins.

    https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.118.035225#d3646671e1

    Or from another review looking at larger changes

    Nevertheless, several RCTs have examined the effect of vegetarian diets on intermediate risk factors of cardiovascular diseases (Table 1). In a meta-analysis of RCTs, Wang et al. (22) found vegetarian diets to significantly lower blood concentrations of total, LDL, HDL, and non-HDL cholesterol relative to a range of omnivorous control diets. Other meta-analyses have found vegetarian diets to lower blood pressure, enhance weight loss, and improve glycemic control to greater extent than omnivorous comparison diets (23-25). Taken together, the beneficial effects of such diets on established proximal determinants of cardiovascular diseases found in RCTs, and their inverse associations with hard cardiovascular endpoints found in prospective cohort studies provide strong support for the adoption of healthful plant-based diets for cardiovascular disease prevention

    https://www.sciencedirect.com/science/article/am/pii/S1050173818300240




  • Yes, this new study has limitations. The authors do note that and aren’t pretending otherwise. This is coming in the context of other studies with similar conclusions which the original article talks about. This new study is a singular imperfect data point, but is combined with other data points that point in the same direction.

    What it is primarily helpful for is in that it has a large N value of 79,468 participants and the population they are looking at doesn’t partake in as many carcinogens that make it harder to tell cancer rates apart (which is both a strength and also a study limitation too)

    From the study

    This study has several other strengths. 1) This is probably the single cancer cohort with the largest number of vegetarians, and especially vegans, who have rarely been studied effectively for cancer incidence. This allows consistent definitions and methods to be applied across all variables; 2) in many studies of vegetarians, vegetarian diets may be relatively transient for some subjects, but less so in AHS-2; 3) the level of validation available for the main variables on which the assignment to vegetarian diets is based; 4) the relatively large Black subgroup in which vegetarian diets have rarely been studied. Race is always a co-variate in our statistical models; and 5) the absence (practically) of cigarette smoking, a common confounder for many cancers, and very little alcohol

    There are also study limitations, the most prominent of which is still the relatively small numbers of less common cancers, particularly among the less common dietary patterns (vegans and pesco-vegetarians) that diminish statistical power; second, there is the relatively health-conscious low-meat-consuming reference group, the Adventist nonvegetarians, that also limits power; third, that we were able to measure dietary and other data only at study baseline and not during follow-up. Finally, there are the limitations of all observational studies, particularly the possibility of unmeasured confounding, which can be limited but never avoided