## 4 Discussion  
The main finding of this study was that, according to their parents' perceptions, children with CD who followed a GFD for more than 12 months had more limitations compared with children who followed a GFD for less than 6 months. In addition, according to the dietary records and parental perception, those children who consumed more than 50% of their energy through UPFs had more limitations, and their treatment was perceived as less effective. On the one hand, the initiation of the GFD can reduce CD symptoms [25] and thus improve the quality of life, but on the other hand, the negative effects on emotional and social areas resulting from following this type of restrictive diet can counteract the initial positive effect. In this sense, a literature review of a sample of 2728 patients with CD highlighted that the GFD significantly improved, but did not normalize, their quality of life [26]. This result is in line with the findings of our study, in which the overall quality  
Figure 3: Differences in quality of life total scores and quality of life domains among children with celiac disease based on the percentage of total energy from ultra-processed foods (below 50% vs. above 50%). (**A**) Differences in limitations subscale based on the percentage of total energy from ultra-processed foods (below 50% vs. above 50%). (**B**) Differences in dysphoria subscale based on the percentage of total energy from ultra-processed foods (below 50% vs. above 50%). (**C**) Differences in health concerns subscale based on the percentage of total energy from ultra-processed foods (below 50% vs. above 50%). (**D**) Differences in inadequate treatment subscale based on the percentage of total energy from ultra-processed foods (below 50% vs. above 50%). (**E**) Differences in quality of life total scores based on the percentage of total energy from ultra-processed foods (below 50% vs. above 50%). Values shown as the marginal mean (standard error of the mean). Model adjusted for age, sex, and parental working status. CD-QOL, celiac disease-related quality of life. Greater scores indicate a better perception of each CD-QOL item (e.g., greater scores for the limitations subscale indicate lower self-perceived limitations). of life was not altered, but more limitations were observed in the patients who followed a GFD for a longer time. These limitations were explored using the CD-QOL questionnaire by asking the patient whether he/she feels limited by the disease, especially concerning social relationships, feels that his/her disease prevents him/her from having a normal life, and feels afraid of food containing gluten, etc. [25]. As the time spent with the illness increases, the quality of life can be affected by the changes resulting from having a chronic disease and the difficulty of having a higher adherence to this strict diet [27]. In fact, a previous study showed that patients who were asymptomatic at diagnosis had a worse quality of life several years after diagnosis than those who had symptoms. Therefore, the CD symptomatology is not the only factor associated with a poorer quality of life [7]. Other studies concluded that the quality of life of people with CD is related to the age at diagnosis, with better adaptation when the disease is detected at an earlier age [28,29]. It should be emphasized that during childhood, the role of parents is essential for adequate adherence to the GFD. In this context, some studies showed significant discrepancies in the perception of the quality of life between children and parents [30]. Generally, the quality of life of children with CD is often perceived as lower by parents than by their own children [29,31,32]. Therefore, the larger limitations affecting the quality of life of the CD children who followed a GFD for more than 12 months may have been more appreciated by parents than other dimensions, such as dysphoria or health concerns, which may be more introspective. It is important to highlight that, on average, 47.3% of the participants' total energy intake came from UPFs.