NO. Eating 6 meals a day has little to do with preserving muscle. 3-4 meals would work just as well for 99% of the population.
The leptin issue can be dealt with by high carb/low fat "refeed" days. Most people dont realize that "cheating" in high gi carbs can produce better results than dieting hardcore for long periods of time.
1gram per lb. of bodyweight is a good estimate and easy to follow. Once could get by actually w/ even less, more like .8g per lb. of lean body mass, but the 1g per lb. is simple and effective, especially since its hard to get a real accurate bodyfat measurement.
1 gram per lb is too much protein.High protein diets are not healthy.1 gram per kilogram is prett much enpough.You should up protein only while cutting keepeng your carbs at 50 5...dont go less then 50