Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:A VARIETY OF MEAL-RELATED stimuli, such as gastricdistending loads (19), duodenal nutrient infusions (11, 30, 31), and meal-induced gut-brain peptides, such as CCK (11), have all been shown to suppress ingestive behavior and food consumption.
Category: