Overweight/obese otherwise healthy volunteers will be recruited from the Old Order Amish population in Lancaster County, PA. Lancaster County, PA. Pharmacodynamic responses to GLP1R agonist will be assessed by conducting frequently sampled intravenous glucose tolerance tests (FSIGT) both before and after semaglutide for six weeks. The proposal proposes two specific aims: 1. Specific Aim #1. To identify genetic variants associated with effects of a GLP1R agonist to enhance glucose-stimulated first phase insulin secretion in the two FSIGTs (before and after administration of drug). 2. Specific Aim #2. To identify genetic variants associated with the effect of a GLP1R agonist to accelerate the rate of glucose disappearance as assessed in the two FSIGTs (before and after administration of drug). Genotyping will be conducted using a high-density array with comprehensive coverage of DNA sequence variants. In addition, the analysis will leverage a global imputation panel generated from 1,025 Amish individuals.