A number of studies have indicated that adolescent obesity is a risk factor for the development of MS, most notably in patients with the HLA-DRB1*15 genotype (Hedstrom et al. Mult Scler 2015; epublished September 11, 2015; Hedstrom et al. Neurology 2014;82:865-872). The relationship between obesity and clinical course once MS has been diagnosed is less clear. A recent study found that obesity (body-mass index >30 kg/m2) did not appear to be associated with increased severity (relapse rate), or disability (EDSS score), nor was obesity linked to the presence of oligoclonal bands (Coban et al. Obes Res Clin Pract 2015;9:533-535).