Last time around, I decided it wasn't worth the hassle of maintaining my membership of the NWCR, so I didn't respond to any of their forms - and they contacted me
three times.
My reasons for not renewing:
* I've always been a bit sceptical about the NWCR's methodology, for example, the continuing emphasis on low-fat food, even though low-fat diets have been discredited for years; their rather flaky definition of "success" (keeping off lost weight for one year); and the fact that they don't make figures on regain publicly available.
* The emphasis on packaged and processed food make it impossible for me to answer some questions, as I outlined upthread.
* The emphasis on "scale weight" discounts the more important issue of body composition. This is a problem for people, like myself, who are into weight training - and a lot of guys want to pack on 10-15 pounds (or more) of muscle. I know it's difficult to accurately measure body fat percentage at home, but a simple metric of waist measurement would indicate whether any regain is muscle or fat.
Anyhoo, I'm kinda over it.