that's an interesting theory ive never heard before. Is it generally accepted that Northern Europeans are taller because their society is less prone to famine?
However it also worth noting that if we go back farther than the past century or so, it was non-european populations that were among the tallest in the world. That would be populations like the Sioux, Athabascans, and Maori. This kind of points to how big a factor social, economic and political context has on population metrics like height. Moreover, certain diets and populations simply make for shorter people. Disentangling all the effects is complicated.
For the data, I'm half-remembering a table from a paper I read years ago. Ourworldindata has a very similar table with pretty reasonable citations, so it checks out:
https://ourworldindata.org/human-height#how-does-environment...
It could also be sexual selection as this stature change is too fast and usually the environment difference takes several hundred generations to show difference.
The timeline is so small I'd argue it's actually free society enabling people to chase their sexual imperitive and this sexual selection is resulting in taller population, not nutrition.