Generally, no. The primary trigger of most cases of acne is the fluctuation of hormones. Hormones stimulate the oil glands to produce more sebum, which can block pores. Bacteria can then grow within the pores, causing them to become inflamed and break out. That happens at times of major hormonal change, such as during the menstrual cycle, and during the teen years, no matter what you eat. So despite what your grandmother told you, eating too many potato chips won’t make you break out in pimples. But there some evidence that certain diets may have an effect on acne, says Macrene Alexiades-Armenakas, MD, PhD, an assistant clinical professor of dermatology at Yale School of Medicine. Studies, such as one published in the Journal of the American Academy of Dermatology, have suggested that high consumption of dairy products raises the risk of getting acne because of the hormones in milk, cheese, and yogurt. However, subsequent studies have not supported the theory. Still other studies of acne's relationship to nutrition have shown that a diet with a high glycemic index, such as white breads, waffles, and other carbs, worsens acne.