Allergies?
I do believe a persons diet has a lot to do with their skin. Not saying everyone
that eats chocolate will break out. Each person with acne prone skin, has to
research what food products causes a skin reaction. I can’t eat chocolate
either. The reason they say milk products is no good for you has partly to do
with the hormones, and by-products that’s found in milk. Also humans are the
only species that use milk past weening. Something to think about. Sugar is
another factor that can cause breakouts. I’m assuming it’s b/c of the high
levels it causes in the body. The body’s sugar level rises and then the hormones
androgens(supposedly the main culprit in break outs) are released.
Just a comment! 
~Willowbirch