This is a 2 part question.
The first part of the question is in the title:
Is getting and staying in Ketosis for a period of time intended to simply help one shed "fat weight" or can it also help one shift body composition towards lean muscle?
My situation is this: I am in good shape and close to my ideal weight, but i would like to see a shift towards a leaner body composition without losing too much weight. I am 22 y.o., 5' 11", 181 lbs (I believe going any lower than 175lbs would be to low for me, and ideally id prefer to lean out but stay at this weight). I am active 7 days a week, and significantly more active on the weekends than weekdays. I am currently eating about 2000 Calories per day (I don't count calories, but i find after paleotracking my foods that when i am satisfied and full, i cant really force myself to eat more than 1900-2000 calories on the average day). Weekday exercise is usually 2 days a week strenuous lifting for 1 hour, 1 day interval training for 40 minutes (Sprints), 1 day Yoga, and 1 day a medium run (5-6 miles) with abs. On weekends I will do 2-3 miles of walking per day accompanied by 2-2.5 hours of pickup full court basketball on saturday & sunday.
The second part of my question is this - I am currently doing a 30 day primal challenge edit*** - I bring up the primal challenge b/c for the next 20 days i am trying to be stricter than usual with my primal eating. When i am not doing a challenge, i will have a cheat meal on weekends or paleo-ize some non paleo baked goods and add those in small quantities over the week to add some extra calories. (paleo challenge except that i include small bits of dairy in my diet), and I am wondering
A) if ketosis will indeed help me shift body composition, how can i remain in ketosis on weekends while still eating enough to fuel my intense "play" days? Should I be eating more carbs than my average daily 75g or so? If I do not add carbs, will i be destroying lean mass? Will I fall out of ketosis if i add carbs?
B) If ketosis will not help shift body composition but will result in my losing weight (AND lean muscle mass perhaps in my case), what recommendations do you paleohackers have about how i can shift my diet to one that will not destroy the lean weight i am trying to cultivate?
Thanks! I know this is a long winded question, but hope some people share in wanting to learn how to tackle this situation. :P