The breakfast tolerance test: a return to physiology.

The effects of a standardized breakfast on blood glucose, plasma free fatty acid and alpha-amino nitrogen levels, plasma insulin, glucagon and cortisol concentrations as well as serum growth hormone circulating levels are described in a group of six healthy, young, male volunteers. It is suggested to the clinician to use this "breakfast tolerance test" or B.T.T. as a simple means to reconsider on physiological grounds some widely accepted pathophysiological concepts derived from highly unphysiological procedures such as the oral glucose tolerance test or O.G.T.T.