I started last Sunday. There are suggestions in his book on how to help with adjusting to coming off all the grains, but what I primarily did was made sure I was hydrated and put a little extra salt. So far, the first week was not as bad as I though it would be. As for your tracker, you can adjust the percentages for your carbs, fats and protein. I lowered my carbs to 10% or so and increased the protein and fat percentages to be higher. You don't really need to, because you're primarily focusing on net carbs (subtracting fiber from total carbs), and MFP is really helpful with that. The more fiber, the less the net carb, the more you can eat. I am watching my calorie intake, and I've found myself ranging from 1,300 to 1,700 calories, and feeling satiated. I highly recommend having yourself hot tea at night to help. There are some days I did consume a little more dairy than recommended, but I also did not eat fruit, simply because I managed to run out.

Hi Ellemarie - this isn't a very active group. We mostly hangout here http://community.myfitnesspal.com/en/group/394-low-carber-daily-forum-the-lcd-group
I am sort of moderately low car - about 100 grams a day. Most of the folks in the low carb groups eat 100% grain and sugar free.