My waist until recently was about 40", and I had no problem fitting into any manufacturer's womens shorts. They stretch. I go by my hip measurement.

I think in order to not have the diaper effect you need shorts that are very form-fitting, so the chamois doesn't bag, and I prefer the kind of chamois that doesn't come way up in back, which looks baggy.

Trashy Cat makes a short, the Satin Short, which Bicycling Magazine named as the best short under $100 in 2005. The shorts are 8 panel, nice elastic, very nicely fitted, with a substantial contoured chamois (pic on the website) which still manages to not be bulky at all. I love them. Don't be intimidated by the models on the site- I weigh 142 pounds (5"2") and fit in the size L with no problems.

Nanci