It has sugar, so naturally it is carb heavy but the darker and less sweetened the better. A little dark chocolate is good for you as it had healthy antioxidants. It is a better choice than other chocolates but eat in moderation.
Just make sure what's in the ingredient - look out for gmos and refined sugars, corn syrup, high fructose stuff. If you are making your own, replace sugar with natural sweetners like honey, maple syrup, coconut sugar etc.
I go with 70% dark.