Actually, calorie restriction has shown to provide life extension in every species tried so far except for one highly over-referenced rhesus monkey study that were contradicted by a later study[1]. Human study results are much more difficult to obtain due to our average life span lengths.

Also there was a recent article that made it to the front page of HN talking about a positive study of intermittent fasting's longetivity-related benefits - which is probably a closely related or identical phenomenon (my guess).

[1] http://www.nature.com/ncomms/2014/140401/ncomms4557/full/nco...