Title: Evaluating Eating Patterns and the Relationship of Diet Quality and Level of Processing to Quality of Life Among Adults and Teenagers With Celiac Disease
Description: Celiac disease, a common autoimmune disease, affects ~1% of Americans. Treatment requires strict elimination of gluten, proteins found in wheat, rye, and barley. Individuals with celiac disease have been shown to have a lower quality of life than others without it. However, their quality of life has been known to improve with adherence to the gluten-free diet. Other than gluten-free diet adherence, little research has been completed on how specific eating patterns may impact the lives of individuals with celiac disease. In the general population, diet quality has been associated with health-related quality of life, where quality of life has been predictive of other outcomes, like mortality. Research in the general population has also shown an association between increased consumption of ultra-processed foods and adverse health outcomes, including obesity, cancer, and premature mortality, but none have explored its relation to quality of life. Among individuals with celiac disease, no studies have explored the relationship between diet quality or ultra-processing resulting from strictly adhering to a gluten-free diet and celiac disease-specific quality of life.

This dissertation describes the eating patterns of a sample of 50 adults and 30 teens with celiac disease (the “sample”) to understand what they were eating, as well as the relationship between their diet quality and level of food processing to quality of life. Results were compared to a representative sampling of the population in the United States from the National Health and Nutrition Examination Survey (“NHANES”). The sample had room for improvement in their diet quality and levels of ultra-processing but performed favorably compared with NHANES. Using the Healthy Eating Index, the majority had scores considered suboptimal (mostly moderate scoring). However, using the Alternate Mediterranean Diet score, fewer had suboptimal scores (mostly moderate to high scoring). Differences between the measures’ scores reflected: (1) variations in measurement criteria, and (2) separate weights applied to those criteria. The sample had ultra-processed food consumption within the range associated with adverse health outcomes in some studies.

With the exception of low folate and high lipids, most of the sample’s nutrient concerns reflected those in NHANES. The sample’s diet patterns were most similar to those in NHANES who had reported prior celiac disease diagnosis and were adhering to a gluten-free diet, with patterns significantly more favorable to other NHANES groups. In the general population, there was a consistent relationship with both higher Alternate Mediterranean Diet score and lower levels of ultra-processed food consumption as a percent of energy to better quality of life. Similar but less robust trends were found with the sample. Overall, results suggested that both higher adherence to healthier diet patterns (for example, more produce, legumes, nuts, whole grains, and less saturated fat) and lower levels of ultra-processing were associated with higher quality of life.