BACKGROUND/OBJECTIVES: Numerous studies have highlighted the nutritional imbalances that are commonly observed in children and adolescents diagnosed with celiac disease (CD) who follow a gluten-free diet (GFD). However, the development and timeline of these nutritional deficiencies remain unclear. The aim of the present study is to investigate the short-term (≥6 months to <
12 months) and long-term (≥12 months) association between adherence to a GFD and nutrient intake as well as micronutrient blood status in children and adolescents aged from 0 to 18 years with CD. METHODS: A systematic review was conducted in PubMed and Scopus for observational studies published up to June 2024. RESULTS: A total of 15 studies (case-control, cross-sectional, and prospective studies) with 2004 children and adolescents were included. Their quality was assessed using the ROBINS-E tool. Despite the lack of high-quality data and the heterogeneity of the methods used in the included studies, the results of the cross-sectional/case-control studies show that, in the short term, children and adolescents with CD consumed excessive amounts of protein and carbohydrates compared to controls. After long-term adherence to a GFD, significant changes in the diets of children and adolescents with CD persisted. Fat intake was higher, while protein intake remained excessive compared to controls. Based on prospective studies, vitamin C and iodine intake improved both in the short and long term after adherence to a GFD. However, most other nutrients either remain inadequate or continue to decline, indicating that it is difficult to meet nutrient requirements despite dietary adjustments. CONCLUSIONS: Gaps in adherence to dietary recommendations appear to be widespread in children and adolescents with CD, emphasizing the need for improved diet quality and regular monitoring.