The obvious question that comes up for me in this survey is, did they correct for the possibility that men actually have it better than women, and that's why men grew more? E.g., did they check heights of women in countries where women's rights are better? I'm not saying the result is wrong, but I didn't see any reporting that answers this question, and it was the obvious question that occurred to me. E.g. in some countries included in the survey, women take a huge caregiving burden on average compared to men because the social safety net is so compromised. How does that affect their ability to thrive? This is not discussed.
Note, for example, the following weasel words from the study:
The reasons for the different cross-country and within-country effects are not yet clear but might be explained by greater noise in the across-country data due to variation between nations and will require follow-up studies.
In other words, they do see variation in different countries, and they have not analyzed it to see if it contradicts their hypothesis. Doesn't mean their hypothesis is wrong, but it's sloppy work. And of course the Guardian article is clickbait, as is the title of the study. Sigh. So I would take this result very much with a grain of salt.
Not that it really matters that much, of course... :)