Nutrient intakes in adult and pediatric coeliac disease patients on gluten-free diet: a systematic review and meta-analysis

: Celiac Disease (CD) continues to require a strict lifetime gluten-free diet (GFD) to maintain healthy status. Many studies have assessed the GFD nutritional adequacy in their cohorts, but an overall picture in adults and children would offer a lifetime vision to identify actionable areas of change. We aimed at assessing the nutrient intakes of adult and pediatric CD patients following a GFD diet and identifying potential areas of improvement. Systematic review was carried out across PubMed, Scopus and Scholar up to October 2022, including full-text studies that assessed the nutrient intakes of CD patients on GFD, in terms of macro- and/or micronutrients (absolute or percentage daily average). Random-effect meta-analysis and univariable meta-regression were applied to obtain pooled estimates for proportions and influencing variables on the outcome, respectively. Thirty-eight studies with a total of 2114 patients were included. Overall, the daily energy intake was 1995 (CI 1884-2106) Kcal with 47.8% (CI 45.7-49.8%) from carbohydrates, 15.5% (CI 14.8-16.2%) from proteins, and 35.8% (CI 34.5-37.0%) from fats. Of total fats, 13.2% (CI 12.4-14.0%) were saturated fats. Teenagers had the highest consumption of fats (94.9, CI 54.8-134.9 g/day), and adults presented insufficient dietary fiber intake (18.9 g, CI 16.5-21.4 g). Calcium, magnesium, and iron intakes were particularly insufficient in adolescence, whereas vitamin D was insufficient in all age groups. In conclusion, GFD may expose CD patients to high fat and low essential micronutrient intakes. Given GFD is a lifelong therapy, to prevent the occurrence of diseases (e.g. cardiovascular or bone disorders) dietary intakes need to be assessed on long-term follow-ups.