Studies show that dark chocolate (70-85%) has more antioxidants than most foods, and has a direct effect on improving insulin sensitivity. But chocolate is also an energy-dense food, it means that excessive consumption of chocolate can contribute to weight gain and health complications associated with overweight .
Although milk chocolate has a similar energy value (2 290 kj / 100 g) to dark chocolate (85%) (2 485 kj / 100 g), you can still choose a more appropriate alternative of it. These chocolates vary considerably in the amount of simple sugar.
Assume that 1 cube of sugar contains 5 g of simple sugars.
The benefits of moderate cocoa or dark chocolate consumption (> 70% cocoa content) outweigh the potential risks of their consumption .
 KATZ, David L., Kim DOUGHTY a Ather ALI. Cocoa and Chocolate in Human Health and Disease. Antioxidants & Redox Signaling [online]. 2011, 15(10), 2779-2811 [cit. 2020-02-11]. DOI: 10.1089/ars.2010.3697.