Yes we eat during a fasting period, we eat vegetables, legumes (beans) rice, and other grains along with some shell fish allowed.
Here is the short answer my pastor gives: "The Church calls on all of us to go without meat, most kinds of fish, dairy products, oil, wine, and hard liquor.Pregnant women, nursing mothers,and growing children should not tryto keep the full fast, and, if you take any medication, then you should follow your physician’s recommendations. However, most of us can keep the full fast, and all of us can keep
the fast is some way, shape, or form. So, be sure and check with your spiritual father before Great Lent begins so that you can get his blessing for the fast." The Voice Newsletter, St John the Forerunner Antiochian Orthodox Church, Cedar Park Texas February 2010.
When in doubt discuss your concerns with your pastor or spiritual father.