The aims of this study were: i) to evaluate the association between plasma GIP change in response to an oral glucose challenge (as a surrogate of GIP secretion) with obesity-related anthropometric measurements, fasting inflammatory biomarkers, and fasting circulating adipokines (including total adiponectin and high-molecular-weight-HMW adiponectin); and ii) to evaluate the feasibility and adequacy of using postprandial plasma GIP as a biomarker of adiposity-related phenotypes in response to starch-based meals of highly controlled composition and microstructure. This evidence concerns the gene GIP and obesity due to melanocortin 4 receptor deficiency.