@imautistic If you tolerate them, it is good to eat more calorie- and nutrition-dense foods such as nuts, eggs, and avocados, and yogurt. I am sensitive to gluten, legumes (beans, peanuts..) and processed foods, and we are all different regarding what we digest well. If your being underweight can be associated with malabsorption (not absorbing all the calories and nutrients that you eat), which can happen with celiac and other conditions. Keeping a food journal and focusing on whole foods, rather than processed can help see if there are any that cause digestive or other problems. Let us know how you are doing. https://www.niddk.nih.gov/health-information/professionals/clinical-tools-patient-management/digestive-diseases/celiac-disease-health-care-professionals