Sneaky Acne Cause No. 3: Diet
The real deal is that an overall unhealthy diet will have an effect on your skin — it’s the largest organ in your body, so how can it not be influenced by the food you eat? Shamban says that having a high glycemic index, which you get by eating foods that spike your blood sugar levels like, uh, sugar and also fried foods, will mess with your body and can cause acne.
Also, some people do have actual allergies to foods like chocolate or dairy that cause them to break out, so if you notice you break out after a candy bar binge or an ice cream marathon then cut back and see what happens.