The moment comes when all muscle 'bulkers' must cut and tone their muscle bound frame, the trouble is that this comes at a cost, usually in the currency of muscle mass! The aim has to be to limit muscle loss whilst maximising fat loss, and in order to do this you should ensure your caloric deficit doesn’t invoke more total weight loss than 0.5 – 1% a week in order to maximise muscle retention. The ISSN suggest that a protein intake of around 2.3 – 3.1g of protein per kg bodyweight is optimal to facilitate this cutting phase.
Helms, E, R., Aragon, A, A, and Fitschen, P, J. (2014). Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. Journal of the International Society of Sports Nutrition. Retrieved 10th November, 2014, from http://www.jissn.com/content/11/1/20