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:In particular, it has been noted that high levels of abdominal fat pose a particularly severe risk for progress to metabolic disease (12–18), whereas fat deposited subcutaneously is more benign (17,19) and may actually be protective (20).
Category: