What role does diet play in acne?

Acne & Diet. Many foods can aggravate acne. The most common culprits, in my observations, are nuts and peanut butter, dairy products (excess cheese and milk), sugars and high glycemic index foods (chocolate). So, no snickers bars; no reese's cups; no gallons of milk, cut down on cheese.
Not much. . If you observe worsening with certain foods, you may wish to avoid them. Acne is caused by a confluence of the effect of hormones, bacteria, oil, and skin debris plugging and infecting skin oil ducts.