zlacker

>>lsllc+(OP)
I'm not going to argue for or against any specific conclusion here, but there are several reasons that observational nutrition studies (and reviews of such work, like this one) need to be taken with a grain of salt, including:

- healthy user bias: People who choose a plant-based diet (or in fact, probably just about any structured diet) are more likely to be health conscious in general and more likely to have other healthy habits like exercise.

- latent variables: "meat eaters" follow a wildly diverse group of diets, including those who eat just fresh lean meats, and those who eat heavily processed foods like bacon and sausage. Or those who eat just chicken. Or just fish, etc. A lot of the contradictory claims about "meat" seem to have a lot to do with these distinctions.

- self-reporting errors: Most observational nutritional studies rely on self-reporting of diet - there's a ton of research that shows that people regularly misreport what they eat in these studies (both qualitative & quantitative).

All of this is not to dismiss the results either - a lot of the time observational nutrition studies are the best we have! Doing randomized controlled trials on these kinds of interventions is difficult, so observational studies are often the best we can get, but they're really only a piece of the puzzle.

>>jonnyc+M9
Do you have any evidence that plant-based diets are more "health conscious", and that that by itself explains why they are healthier?

I'm personally vegan for ethical reasons, not health reasons. I wonder how many people actually go plant-based for health reasons, I doubt it's the majority.

>>paullu+Kd
The "healthy user bias" is a well-known phenomenon in this kind of research, and has been studied specifically with vegetarianism (for example, https://journals.lww.com/nutritiontodayonline/abstract/2019/...). But as mentioned in the comment, I suspect you'd find a similar bias in all sorts of structured diets - the group of people who follow diet X (including sub-groups who follow for health reasons, or moral reasons) will be biased towards being more health conscious.

Again, this doesn't negate the research on "diet X", but it does make coming to a conclusion more complicated.