A diet high in refined carbohydrates, like starchy and sugary foods, can make insulin resistance, high-fiber foods can help to combat insulin resistance by slowing down digestion reducing the impact of sugar on the blood which helps PCOS. Great options for high-fiber foods include: cruciferous vegetables, such as broccoli, cauliflower, Brussels sprouts, greens, including red leaf lettuce, arugula, green, red peppers, spinach, kale, beans, lentils, sweet potatoes and pumpkin.