To determine the food sources of energy and 13 core nutrients, 89 diet recalls were analyzed from an explanatory mixed-methods pilot study with adults following a gluten-free diet (GFD) for any reason. Nonconsecutive dietary recalls were collected through a web-based, Automated Self-Administered 24-Hour (ASA24®-Canada-2016) Tool. Mean nutrient intakes were compared with Dietary Reference Intakes. Food items (excluding supplements) were extracted and categorized according to the Bureau of Nutritional Sciences Food Group Codes. Percentages of total dietary intakes from food sources were ranked. Grain products were the highest ranked contributor of energy (21.4%), carbohydrate (30.3%), fibre (29.1%), and iron (35.3%). Breakfast cereals, hot cereals, yeast breads, and mixed grain dishes (mainly rice or pasta-based) were the most important nutrient contributors for grains, despite most (64.3%) commercial cereals and breads being unenriched. Legumes and seeds were not frequently consumed. Nutrient density in the GFD could be improved with more emphasis on gluten-free (GF) whole grains, legumes, seeds, and enriched breads and cereals. More research is needed on the nutrient composition of GF foods to identify food sources of folate, other B vitamins, zinc and magnesium-nutrients of concern for those requiring a GFD.