Accutane is a synthetic form of Vitamin A and too much Vitamin A can be toxic. I generally advise patients to avoid supplements with Vitamin A while taking Accutane. If you eat very large amounts of Vitamin A containing foods (like carrots), you should discuss this issue with your doctor.
Accutane can also increase your cholesterol and triglycerides, so fatty meats, high-fat dairy (like butter or cream), and starchy foods should be limited. Fresh fruits and vegetables, along with whole grains, are usually a good choice. Some fat, however, is needed to absorb the medication so it should be taken with at least some fat (whole milk, cheese, etc.).
Accutane can irritate or damage the liver so alcohol should be avoided while taking it.