I thought about doing CR for a while - I read the "120 Year Diet," and was considering giving it a try. Then I met up with a couple who was into hardcore CR. I had dinner with them. Two things made me decide not to do it:

1) they seemed frail and weak - the man seemed to have a constant runny nose. I felt that if he fell down he would break his hip. The risk of injury and death from physical weakness seemed like it would counter any benefits from CR for lifespan.

2) They put so much effort into measuring every ingredient, and running computer programs with recipes to get the optimal nutrients with as little calories as possible. It seemed to take so much time in preparation, and you could mostly only eat at home.