Gluten / grains
According to studies by the Massachusetts General Hospital and Dr. Alessio Fasano, almost all of us have some sensitivity to grains and gluten, and acne flare-ups could be a result of consuming too much gluten.
The reason why gluten and grains can be problematic for your skin is basically the same for when you consume sugar. Gluten causes the production of IGF-1 in the body, which is a form of the hormone insulin. The more you produce, the more sugar is absorbed, in turn blocking your pores and causing more sebum production.