Only 11 g of carbs per 20 g bag? Seems safe to eat a bag, but I guess that would depend on your carb tolerance. I've never tried that stuff, but I'd be tempted.
Lots of low carb good-for-you foods are also good to eat - e.g. steak or strawberries and cream... so don't think that virtuous eating and yukky food necessarily have to go together!
The main thing is : what does your meter tell you about your lentils?