To answer that question, you must know the type of chocolate you’re eating.
A study by Dr Claudio Ferri, published in the American Heart Association journal, Circulation, saw 15 healthy volunteers randomly assigned to eat either a 100g dark chocolate bar rich in polyphenols, or a 90g white chocolate bar, which does not contain polyphenols.
These bars were eaten every day for 15 days.
After eating no cocoa or chocolate for a week, the volunteers then switched to the other type of chocolate.
Compared with white chocolate, the dark chocolate was associated with lower blood pressure and with improvements in insulin resistance and insulin sensitivity, which are important markers for diabetes.
A similar study by Dr Ferri is of even greater clinical importance. This was carried out in patients with high blood pressure.
The study found that dark chocolate, but not white chocolate, decreased blood pressure and serum low-density lipoprotein (LDL) while improving blood flow and insulin sensitivity.
Interesting studies by other researchers suggest that cocoa proanthocyanidins (flavonoids which are powerful antioxidants) prevent the elevation of blood glucose levels in diabetic obese mice.
So, the short answer is this: some chocolate is far better than others. If you’re going to eat it, choose dark chocolate and do it in moderation.