Hi!
There could be a few things...
first, the tuna salad. if it's prepared, there may be some sugar in there. Ask to see the ingredients list.
Also, advantage bars are notorious stallers and in my opinion, not worth it for the taste alone . There are tons of hidden carbs in them, and they could be adding way more carbs than you are bargaining for!
You also need to make sure you're getting your veggies in! They are important (and, after you eliminate the bars and figure out the tuna situation) should be your primary source of carbs. Atkins recommends salad and veggies, re-read the induction chapter for the specifics,I believe it's 3 cups of salad or 2 cups of salad plus 2/3 cup of a low-carb veg, but I could be wrong.
And...water! Make sure you drink at least 64 oz a day. It makes a big difference for a lot of people.
Some things to think about....best of luck!!! Hang in there!
Susan
PS forgot: the sprite. artificial sweeteners can also adversely affect some people. I would replace it with water at least for the first 2 weeks, then after that see how much you can tolerate, but remember, it won't count towards your water.