I think the original post was a bit confusing in what it claimed the Faunalytics study was useful for.
For example, the section
The ideal study is a longitudinal RCT where diet is randomly assigned, cost (across all dimensions, not just money) is held constant, and participants are studied over multiple years to track cumulative effects. I assume that doesn’t exist, but the closer we can get the better.
I’ve spent several hours looking for good studies on vegan nutrition, of which the only one that was even passable was the Faunalytics study.
[...]
A non-exhaustive list of common flaws:
Studies rarely control for supplements. [...]
makes it sound like the author is interested on the effects of vegan diets on health, both with and without supplementation, and that they’re claiming that the Faunalytics study is the best study we have to answer that question. This is what I and Matthew would strongly disagree with.
This post uses the Faunalytics study in a different (and IMO more reasonable) way, to show which proportion of veg*ans report negative health effects and quit in practice. This is a different question because it can loosely track how much veg*ans follow dietary guidelines. For example, vitamin B12 deficiency should affect close to 100% of vegans who don’t supplement and have been vegan for long enough, and, on the other side of the spectrum, it likely affects close to 0% of those who supplement, monitor their B12 levels and take B12 infusions when necessary.
A “longitudinal RCT where diet is randomly assigned” and that controls for supplements would not be useful for answering the second question, and neither would the RCTs and systematic reviews I brought up. But they would be more useful than the Faunalytcis survey for answering the first question.
I think the original post was a bit confusing in what it claimed the Faunalytics study was useful for.
For example, the section
makes it sound like the author is interested on the effects of vegan diets on health, both with and without supplementation, and that they’re claiming that the Faunalytics study is the best study we have to answer that question. This is what I and Matthew would strongly disagree with.
This post uses the Faunalytics study in a different (and IMO more reasonable) way, to show which proportion of veg*ans report negative health effects and quit in practice. This is a different question because it can loosely track how much veg*ans follow dietary guidelines. For example, vitamin B12 deficiency should affect close to 100% of vegans who don’t supplement and have been vegan for long enough, and, on the other side of the spectrum, it likely affects close to 0% of those who supplement, monitor their B12 levels and take B12 infusions when necessary.
A “longitudinal RCT where diet is randomly assigned” and that controls for supplements would not be useful for answering the second question, and neither would the RCTs and systematic reviews I brought up. But they would be more useful than the Faunalytcis survey for answering the first question.