My once-every-three-weeks column for the San Francisco Chronicle is set up as a Q and A. I don’t get many questions through the column, but the few that do come in are often quite challenging. This one is from a school chef wondering how to deal with kids who might be gluten intolerant – and whether gluten intolerance is becoming more common. Interesting questions! Here’s what I had to say about them. If you have questions about food and nutrition that you’d like me to answer, send them to firstname.lastname@example.org (put Marion Nestle in the subject line).