All those who are not really a fan of dark chocolate will be happy to hear that taking a look at the nutrition facts shows: dark chocolate has at least (if not more) calories than milk chocolate. 

But is it healthier? Various studies in recent years have shown that dark chocolate is very beneficial to health due to its high/higher percentage of polyphenol. Researchers have found evidence that those positive effects apply to cardiovascular, neurological, intestinal as well as metabolic diseases (Magrone et al., 2017; Sentürk & Günay, 2015; Shaha et al., 2017). 

Isolated studies (Golomb et al., 2012; Farhat et al., 2014) even revealed a relation between a reduction of body weight and the consumption of dark chocolate. However, these results should not encourage an unrestrained consumption of chocolate. The studies neither provide insight into the amount or frequency of consumption nor the percentage of cocoa. Accordingly, the studies' results should be interpreted with caution.