Look at the label for the term "partially hydrogenated" to avoid trans fat.

CNN: updated

"Some chocolate bars are high in saturated fat or partially hydrogenated fats - trans fats - which may increase inflammation, possibly contributing to inflammatory acne, " she says, adding that this theory has not yet been proved.

BBC: Does chocolate give you spots?

Trans fatty acids constitute up to 60 percent of the fat in processed foods containing hydrogenated fats.

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