Interesting study from Norway. Gist is that if you want to trim down to your racing weight while maintaining power and performance, you should shoot for losing no more than 0.7% of your body weight per week. For someone who's 160 pounds, that's 1.1 pounds/week. Caveat: Study subjects were elite athletes.

http://www.ncbi.nlm.nih.gov/pubmed/21558571