Q. I get headaches when I try to go vegetarian. Help!

A.The likely culprit of your pain is anemia, says Brooke Alpert, RD, a nutritionist in New York City. “Going the veggie route without having a well-thought-out plan can lead to both iron- and vitamin-deficiency anemia, which can bring on headaches,” she says. To avoid this side effect, make sure you get enough of the following foods: soy and fortified cereals (for vitamin B12); dried fruit and green leafy vegetables (iron); and eggs, if you’ve decided to eat them (an excellent source of many key nutrients). Adequate amounts of complete protein will also help you feel your best, so reach for peanut butter on whole-wheat bread or cook rice and beans—both meals provide the essential combination of amino acids, says Alpert