According to a 2008 study published in the journal Molecular Nutrition & Food Research, what you eat can affect your skin. The study’s Australian researchers measured the effects of high- and low-glycemic diets on the skin of teenage boys. The glycemic index of a food defines how quickly it’s broken down into glucose by the body. High-glycemic foods, such as refined carbs, sugary drinks, and even certain fruits high in natural sugars, cause large spikes in blood sugar when eaten. Low-glycemic foods, such as whole grains, are broken down into sugars more slowly, so they do not cause spikes in blood sugar. The researchers found that those who were on the low-glycemic diet experienced a 50% reduction in acne, while those who ate the high-glycemic diet experienced a 14% increase. Researchers speculate that insulin resistance—commonly associated with eating a high-glycemic diet—may fuel inflammation and the production of the acne-causing oil sebum.