In humans, testicles tend to be more figurative than literal. When you say "he has big balls" I suspect you didn't actually LOOK at the guy's testicles. Besides, in the modern use of the term, females can be said to have balls, and I'm pretty sure they anatomically don't.
Part of the issue is that human testicles are a bit hidden at baseline, and when you add a few layers of clothes you don't see them at all (unless you have filariasis).
But all of that could change. With yogurt.
In a recently published study bound to send gangsta-rappers to the nearest dairy aisle, they found that male mice fed only yogurt developed larger and heavier testicles (5%-15% increase ) over mice on other diets. They also developed a characteristic posture of projecting their jewels outwards, which in turn gave them a "swagger" when walking. And (of course) they had better hair.
At this point I suggest you pause. Because you've probably got an image of a swaggering, big-balled, nice-haired mouse eating Yoplait listening to a megavolume boombox stuck in your head, and you'll need a minute to get over it.
The application of this in humans is staggering, but quite frankly I don't WANT bigger balls. I mean, walking can be klutzy enough as it is without putting more things in the way. The last thing I want is to go through life like Angus Young.*
The nicer hair I'm interested in. Hell, at this point in my life I'm interested in ANY hair. But I think I'll stick with Minoxidil.
I can see wanting to swagger here and there, like when I save the day at the hospital and don't have my cape with me (oh hell, I'm a neurologist, who am I kidding?), but I'm generally happy sitting at my desk in a quiet office. And when you spend most of the day on your rear end, bigger balls just get in the way, and you have to waste time readjusting them.
The article ended by noting that similar studies of yogurt, testicles, and "semen quality" in humans have been "consistent" with the mouse data. I have no idea who's volunteering for this. "After finishing the yogurt, take this magazine and a cup into the restroom."
Since I already have 3 kids, and would rather be comfortable at my desk, I'm glad that Diet Coke now comes with vitamins and minerals (can we have one with Minoxidil, too?). I'll get my calcium there, and leave the yogurt to those who prefer it with nuts. Big ones.
Thank you, Moose!
*If you understood the reference before clicking the link, then you're old. Like me.