I note that your statement is appropriately very strongly hedged.
> So, based on all existing research and in the context of a normal diet,
Dietary “science” has one of the lowest standards of rigor of any field, in the same ballpark as psychology. Until we have accurate computer models of every metabolic pathway in the human body, I’m not going to trust papers that are like “actually you can just eat soy and seitan and be fine” (incidentally, the counterfactual study got funding approval from vegan activists and seventh-day Adventists!). Also, “in the context of a normal diet” is another pretty big hedge - “normal” diets are terrible.
In any case, when we’re talking about nutrition, since the state of research is so bad, we’re basically stuck with a priori reasoning and Bayesian observation, and after applying those two, my observation is that people who eat only ruminants and fish and stuff look really good and are strong and healthy, and the exact opposite is true for people who eat only vegetables, and this doesn’t really impose a big update on my prior derived from what I know about pre-agriculture food sources in these people’s evolutionary environments.
> Because beef is tasty.
As you point out, when your body makes something taste better than something else, it’s probably because it’s doing a better job of meeting your nutritional needs. If two foods were abundant in the evolutionary environment, I expect taste to be reasonably well-calibrated in terms of causing me to eat the nutritionally optimal distribution of foods.
Ruminants and birds were both abundant in my evolutionary environment. So what does it say that ruminants taste so much better?
Modern dietary science is quite different from it’s starting point. We know enough for soldiers, inmates, etc to eat exactly the food provided and be healthy. That’s the basic benchmark for success.
> it’s probably because it’s doing a better job.
Many birds are quite tasty, chicken however wasn’t part of our evolutionary environment. It also breaks down in the wider context, evolution would be adjusting things based on the overall diet and lifestyle of our ancestors which based on available evidence was quite different from our own.
Chickens are easy to farm which is why their so common, but they aren’t that representative of other bird species.
People may for example need on the order of μg/day of Bromine, Arsenic, Nickel, Fluorine, Boron, Lithium, Strontium, Silicon and Vanadium based on organic compounds containing them, but the need is slow low their plentiful in any reasonable diet. So sure, if you where building a food synthesizer from inorganic compounds then nutrition is quite complex, but in terms of diets people generally self regulate quite well with cravings often occurring should a deficiency develop.
Start looking for what’s not either sufficiently plentiful in most foods or synthesized by the body and you end up with a rather short list. Vitamin C is mainly an issue because it’s destroyed by cooking, and even then people can literally go months without developing systems even with zero vitamin C. Thiamine is another one that became an issue when people started eating a lot of white rice, but again it’s food prep not the plant that’s the issue. Many arguments around optimal diets exist, but the original quote was safety not say Olympic athletes.
So, based on all existing research and in the context of a normal diet, no there isn’t a significant nutritional benefit to beef over chicken.
> switch to beef
Because beef is tasty. It’s the same reason people don’t need to be convinced to eat chocolate.