Ugh, I can't stand it when people directly blame individual things for breakouts.
A breakout is caused by any number of things: a mixture of your endocrine, digestive, circulatory, lymphatic and immune systems, and many more are involved, as [shock horror], everything in your body is actually RELATED. Things interconnect. You can't blame chocolate for your breakout individually, as anything you put into your body can impact upon your complexion, and everything else [these other things can also impact upon your complexion, directly and indirectly]. Its about your blood, how your body deals with and disposes of hormones and toxins, hormone activity, your immune system, your health, your diet as a whole, how much overspill of toxins there is from your blood into your sweat, your level of sensitivity and amount of exposure you have to pollutants, allergens, irritants and sun exposure, your skincare routine, your exercise routine, your temperature, stress levels, hereditary factors... you can't blame any little thing for breakouts, as people react to different foods, products and changes in different ways. Chocolate has both its benefits and its disadvantages.