I’m not so sure that Popper would be so happy.

There is a section of your post, “But the laws of thermodynamics DO work the same in all living creatures and in all systems for that matter. So rats or monkeys or mice or armadillos are going to obey the laws of thermodynamics in the same way we humans do. And thermodynamic data we gather from well done animal studies applies to humans just as it does to the animals in question.”, the conclusion of which (the last sentence) does not logically follow from the previous two sentences, has not been independently tested and does not appear testable. Even if it resulted to happened in some case (and I underline “if”), you can’t possibly say that it would be true in all cases: you can only reword it to refer just to that well specified case.

Of course the laws of physics will be the same for all animal species, but different species may apply them differently and make different use of them. That is why the third sentence does not derive logically from the two preceding it.

Think of the law of gravity. It’s the same for all animals, but some animals jump higher or even fly: that shows that, even if a law of physics works entirely in the same way for all species and all animals have to obey it, the way they do it may produce completely different results.

The fact that mice, unlike humans, continue to grow throughout their lives seems to me a good candidate to indicate a difference in that sense.

In this case in particular, I’m not clear what this study is showing that we didn’t know already from human research.

We knew already, from case studies, randomizes studies and more recently even longitudinal long-term studies of humans, that ketogenic diets produce short-term weight loss, but that the weight is regained after a year or less. Exactly as with all other diets.

Could it be because, at the end of the day, humans can’t keep on ketogenic (as well as other) diets, although the mice did not have a choice?

Or could it ALSO be due to other differences between humans and mice, of which we know nothing yet?

Finally, Popper does not phrase his theory in terms of “valid”, “good” or “bad” hypotheses and theories, but “scientific” or “metaphysic (pseudo-scientific)”. It’s an important difference, because you can have a false (so, not valid) scientific hypothesis.

I have no idea how to obtain these mice. Perhaps through a laboratory supply house. Good luck.