I find that a lot now with vegetables and fruit. Granny Smith apples now seem to come mostly in grapefruit size and some of the peaches and nectarines seem to be getting to about the same size.

Yes! This enlargening of produce is awful. I must sort through the bin to find anything small enough. Plus the larger ones really do have less flavor.

Supersizing has infected everything.

I've seen the giant jalapenos for a while now, and I still tend to pick out the smaller ones from the bin. But what bothers me is that they seem to have little or no heat these days. I'm not really much of a hot pepper lover, but I do like some heat when I put them on a pizza or something.

So it's probably a combination of factors.

-Thank Texas A&M. Jalepenos are one of the crops that gets the most R&D because it's really commercially valuable. They are always trying to push and perfect the jalepeno for various qualities.
- There are dozens of varieties and each one produces a different style pepper.
-Even with a variety, the spiciness of a jalepeno varies a lot. Check out the Scoville unit range for each one. Two peppers from the same plant can be dramatically different, one being three or four times spicier than the other.
-Your grocery store might have changed what supplier it's using for these peppers, or the wholesaler might have. They might be buying from a new region and ended up with different variety peppers.
-I suspect the restaurant market is selecting for larger jalepenos - the likes of Chili's, with their popper appetizers, must use millions of peppers a year. Growers grow for the market.