(a) Oral minimal model (OMM). (b) ‘Hot’ or labelled oral minimal model (OMM*). G, total plasma glucose concentration; Gmeal, glucose coming from the meal; Rameal, rate of appearance of Gmeal; Rd, rate of glucose disappearance; Rdmeal, rate of disappearance of Gmeal; X and X*, insulin action on glucose disposal and production; NHGB, net hepatic glucose balance [24].