If you did a search on "low carb bars" on this forum you would get hundreds of threads discussing the good and bad.

What it boils down to is this: Some people are affected by the sugar alcohols and others aren't. The "sweetness" of the bars tend to trigger an insulin release in some which causes the weight loss stalls. Others it doesn't seem to matter.

So you are the only one that can tell if those bars will mess up your diet or not. Me personally there are enough chemicals in those things to preserve a horse, something I can do without.