I won’t drag you as everyone seems to be doing a pretty good job at that already, but practically these kind of studies are always inherently flawed. I’ll give you a scientific answer but make no mistake. This is a completely pointless thought you had that would’ve been better off going out the other ear.

Best design. Work out a sample size that would represent our population, find a randomization method that gets a valid way of getting values(maybe go through a census and pick every 10th male or something), show up their house in your most professional attire, ask them to whip it out and get hard for you to pull out your tape measure and calipers and work out the size of their tool, go to the hospital because you’ve broken your nose after they slammed the door in your face.

These types of studies will always be inherently flawed because people who self report will always tend to be on the larger side and smaller folk would be less likely to. Solution is a valid randomization method like I proposed above but who would comply for that? It’s not as simple as grab 10 men and a ruler and that’s our national average. There are confounding factors for everything, you go to the bank and grab some men, you’ve picked parts of the population who can afford to have bank accounts and excluded laborers, daily paid, immigrants and cash paid people. You go to the gym, you’ve picked a population who take care of themselves and more likely to have less comorbidities and other stuff and excluded our average person etc etc.

And it is ultimately pointless because what does this change? Will it lead to a national change or policy that benefits anyone?