I have a similar situation that hopefully will give you some confidence.  I was not on the Atkins diet, but on the Zone diet, which is a bit lower protein than Atkins, althougher still higher protein than most diets, and a bit higher carb, although only low-glycemic carbs are preferred.   While I did the Zone diet 15 years ago and lost 26 pounds in 4 months and kept it off for 10 years, After gaining much weight in the last 5 years due to emotional eating during an enormous amount of stressful life situations, I decided to be strictly on the Zone diet.   I only lost 3 pounds and stuck.  That's when I figured maybe my metabolism was completely shot due to all the stress and junk I had eaten.  I saw Dr. Hyman's book on the shelf, and thought I should do it.  It made sense, although I was nervous at the low protein content for the breakfast and lunch plans, because I know that if I don't have my eggs or some other protein in the morning, I usually get low energy, headaches, and major hunger/cravings by late morning.  But, I went ahead with it and thought, how bad can it be to try something for 7 days?  I was so surprised within the 2nd day, I noticed I wasn't hungry or craving at all, plus I had more concentration and energy than usual.  I'm on my 7th day of USD today, and each day has gotten better.  For one thing, making sure to eat about 2 cups of vegetables at lunch and dinner is lots of carb quantity, but lots of low-glycemic carbs, which are always approved.  The fruits are in limited quantities, again taking low-glycemic ones with the berries as the preferred choices. My husband even asked me if I thought I was getting enough protein to balance the carbs, and I responded to him that I guess what's happening is that when I take out all the junk I was eating and adding in more whole foods, my protein needs have changed.  It took a lot of protein to balance the high-glycemic foods I was eating before, which is why I was hungry/craving/crashing.   In this 7 days, I have lost 8 pounds.  While the Zone diet was awesome in my early 30's, and I would recommend it to others, for me in my late 40's with a metabolism that was no longer normal, it did not work for me this time.  In my opinion, you should stick with USD and see if it helps you get over the blockwall you have reached because your metabolism probably needs a kickstart as mine did.  You're not very likely to regain weight you've already lost.