Mia, it's not advisable to have a second bar, but if it is the difference between having a bar and falling off the wagon, or feeling sick, then you could have a bar, but the consquences may be that you go out of ketosis or don't lose as much, but I'm really not sure. If you can increase your water intake and do a bit of extra exercise, say 200-300 calories worth, it may negate any repercussions.
But before you do, how about having some hot bouillon if you are really hungry. Have a cup of this half an hour before your soup. Coke zero and Dr Pepper zero is also allowed. Plus of course water, tea and coffee. These could fill you up making you feel more satisfied when you have your soup.
Why not try these before having a bar?
This works for me:
Shake for breakfast with plenty of ice and water
Bar for lunch, but if I can, I cut about a quarter of the bar off and have that about an hour after the soup I have for supper. I nibble it slowly and really look forward to it.
Also, to make my soups go further and feel more filling I put some hot pepper sauce (Encona Hot is my favourite), and at least double the amount of water so I get 500-600mls of soup. I add a small amount of fresh parsley or coriander depending on what flavour I have.
A couple of times I have been so hungry I have had to have another soup making 1 shake, 1 bar and 2 soups. Otherwise I would have hit the fridge or fruitbowl. That was before I was in ketosis, and I am finding it a bit easier now, but I am still pretty hungry by mid evening. I'm teaching myself that it is normal to feel hungry between meals. That's the way we evolved. It's new for me because I always grazed when I was bit peckish or bored, or just fancied something, and I still had three meals a day. That's why I put on all the weight.