Caroline Albanese,

The proper name of the diet you refer to is "Cyclic Ketogenic Diet" or CKD.
 An address for finding out more about this approach is
[log in to unmask]

This diet is mainly used to reduce % of body fat.  The diet is not used by
most bodybuilders when they are trying to increase muscle mass.

The principal of the diet is to be in a ketogenic state for 5.5 days of the
week to maximize fat lose, then for approx. 30-36 hrs. eat plenty of
carbohydrates in order to put glycogen back into the muscles.  This approach
to dieting is only recommended to people who exercise, preferably resistance
training, because you need to deplete the muscles of stored glycogen in order
to maximize fat lose.  Most ketogenic dieters that weight lift find that
periodic "carb ups" help them perform better in the gym (retain LBM).  You
could do a CKD using paleo foods, although most bodybuilders "carb up" on
what ever food they like.

CKD is a start towards "periodization of nutrition".  However, like everything
 else  the body will adapt to CKD.  For optimal results, using different
nutritional approaches and varying exercise patterns may be necessary.

Ed Campbell, DC,CSCS
p.s.  I'll be offline for a few days.  See you next week.