Acnes are a very problem of every individual, especially teenagers. And I do beleive that what we eat has a big impact on our skin. If you've always believed chocolate and oily foods cause acne, it's finally time to put that myth to rest. Foods that spike your blood sugar levels can also push your body into making extra insulin, which, she adds, increases the production of cortisol. In general, cortisol acts as our body's immediate source of energy.