The effect of diet on heart disease has been widely studied. As part of this general area of investigation, researchers were interested in the short-term effect of diet on endothelial function, such as the effect on triglyceride level. To study this, they designed an experiment in which 20 healthy subjects were given, in random order, a high-fat breakfast and a low-fat breakfast at 8 A.M., following a 12-hour fast, on days one week apart from each other. Serum triglyceride levels were measured on each subject before each breakfast and again 4 hours after each breakfast. If you had access to all of the measurements collected in this experiment, how would you analyze the data?