I'm down 58 pounds now, and none of my pants fit anymore—they just fall right off. I don't want to get new pants yet, though, because I'm still trying to lose more weight. So, I just bought a new belt, six sizes smaller than my last one, and I'm already on the third notch on the new one. It's the most craptacular belt I've ever seen. I didn't expect much from my $10 leather belt, and this one certainly delivered on my low, low expectations. It looks okay (certainly not good), but it feels vaguely like it's made of cardboard with a veneer of fake leather. When you move it around it makes a variety of subtle squeaking and cracking sounds.
Once I get down to a stable (and hopefully lower) weight I'll have to go on a shopping spree and pick up new clothes and a nicer belt. For now, the interim belt will have to do; I don't have any intention to buy a bunch of clothes and then have them be too big again in a couple months. I think that I probably would wear size 34 pants now. (That's a guess; I haven't actually tried on any new pants.) The average American white man's waist size is apparently 38 inches, which is probably more like size 36 or so given how generous sizes usually are. That seems to mesh with the distribution of sizes I see on clothing racks. I wore a 40 a couple months ago, so I've at least fallen from above average to below average.