Hi Mayflowers. I guess the only way to know is to try, since everyone responds so differently. You have already lost significant weight using consistent low carb, correct? Essentially, it sounds to me like you're looking to add more variety to your diet some days, with additions similar to those allowed on the South Beach Diet. If that's the case, there is a devoted support section in this forum for that diet and someone more familiar with it could probably give you good advice if you post questions there. Here is a link in that section which compares Atkins and SBD:

http://forum.lowcarber.org/showthread.php?t=255875