Celiac disease is a disorder commonly diagnosed during childhood. The treatment is a lifelong gluten-free diet. Both the condition and the diet can influence the children's physical and emotional well-being. The main goal of this observational study is to learn about nutritional status in a group of children with celiac disease compared to a group of healthy children. The nutritional assessment includes information on diet, biochemical measurement, and body composition. Quality of life will also be assessed. The study can contribute to ensure good health and well-being in children on a gluten-free diet.