> My nutritionist tells me that recovering this quickly would have probably been just about impossible for a vegetarian or vegan, without having an iron infusion done.
"probably been just about impossible" doesn't mean "impossible", it more likely means changing your eating habits to a point where you'd have to be really conscious and careful of what you eat iron-wise unlike someone without Celiacs (vegan or not) or someone who likes and can afford beef and can eat as much of it as they want.
There are lentils, beans, tofu, dark leafy greens and other sources of iron. There are iron-fortified foods. IIRC there are other considerations that might prevent careless or food-addicted people from getting enough iron like vitamin C to help with the iron absorption or not eating foods that decrease it.
There are plenty of vegans with Celiacs who manage their iron adequately. But even if you're one of those cases where iron needs to be supplemented, even IV - why not? If you disregard all the arguments against beef or animal products in general it's easy to make the argument that beef would be the best solution.
This reads like appeal to authority (the nutritionist) but a lot of nutritionists take the easy road ("just eat beef") or aren't good at all (haven't kept up with research). That's true of the majority of doctors and the majority of programmers (something people here will be able to relate to in case they haven't realized how useless most doctors are). I've been in and out of hospitals for several relatives for years and have heard doctors tell me outright falsehoods that show they have a only basic understanding of something. That makes sense since those doctors must know about so much more than the patient (thousands of diseases, lots of scientific knowledge about biology) but with a depth-first search into a topic you can spot how most of them have either stopped reading new studies or have lost their motivation to explore all option or have just stopped caring for providing the best kind of care. I hope people here don't have to go through what I have. That was a bit of a tangent, but I already wrote it so I'll keep it as a mini-rant.
> Beef is kind of an important thing in our diets, that's all. Now that I'm back to a more normal level I'll go back to eating less of it, but I am now very conscious how important red meat is in a rounded diet.
That's not really true. I'm sure you could ask vegans or vegetarians or Hindus or anyone who doesn't eat beef but has Celiacs and you'd get a whole bunch of options for managing it. Sure, you'll find ignorant people who think eating fruits all the time is enough but that's the same kind of carelessness that leads to non-vegans eating the standard Western diet all the time or doing other basic mistakes.
The same is true for almost everything. Almost nothing is "an important thing in our diets". People live without nuts or fruits or vegetables or legumes or meat or eggs or dairy (not all at once, of course, although I wouldn't be surprised if someone managed to avoid all these) and are able to manage pretty much any disease other groups of people can manage.
> calories are only part of the picture when it comes to food
True, people should care about the macros and micros. But with the internet it's trivial to do so both wrt learning what does what and how much is needed, and to track how much one eats from each.