The oral-systemic link between obesity and oral disease is intimately tied up with diabetes in a "three-way street."
Genco R. The Three-Way Street. From: Scientific American, Oral and Whole Body Health. October 2006.
Mealey BL. Periodontal disease and diabetes: A two-way street. J Am Dent Assoc. 2006; 137: 26-31.
Simpson TC, Weldon JC, Worthington HV, et al. Treatment of periodontal disease for glycaemic control in people with diabetes mellitus. Cochrane Database Syst Rev. 2015 (11): CD004714.