My 16 year old daughter has been struggling with her weight. Last year, she weighed 90 pounds and maintained the weight. She exercised regularly and ate very healthy. Then that winter (2010), she lost 7 pounds over about a month for no reason. She was eating the same and still exercising regularly. Oddly enough, a month later she began gaining weight...she put on about 15 pounds in just a month. She is the healthiest eater and exercises.Many doctors automatically assume she is anorexic because she is still small with the weight gain, but she definitely does not suffer from an eating disorder. My concern is that when she does gain the weight, she literally looks pregnant that's how bloated her stomach gets.That's One thing that I've noticed is that she puts on "water" weight. And is usually after she consumes gluten and soy. She has been tested for Celiac disease before, but it came back negative. Could she be suffering from this and just have a false negative test? She does get stomach cramps, diarrhea, nausea, headaches, fatigue, etc. What could be causing this?