Earlier quoted context omitted.
Overweight and obese men are more likely to have lowered sperm counts[1] and obesity has tripled since 1970[2]. [1] https://www.healthymale.org.au/news/obesity-overweight-can-i... [2] https://www.who.int/news-room/fact-sheets/detail/obesity-and...
Surely it cannot be that hard to control for weight when doing a study on testosterone amounts in the body? i.e. we have half the sperm, but that's overall - do people who have a healthy weight also have half the sperm?
We don't have enough information. We don't know how they collected their data, we don't know how they analyzed it, even if we did most of us don't know enough to judge those methods etc.
Most "science" is honestly worthless crap done by some random person mainly because they want a PhD or are trying to pad their publication count. They look for some arbitrary thing to test, half-assedly design a study, collect as little data as they can get away with, do a little p-hacking and such to make sure the results are significant (otherwise the time was wasted) then they publish.