Blood glucose patterns and appetite in time-blinded humans: carbohydrate versus fat

We assessed the extent to which a possible synchronization between transien t blood glucose declines and spontaneous meal initiation would lend support to the interpretation of a preload study with isoenergetic (1 MJ) isovolum etric high-fat or simple carbohydrate (CHO) preload drinks. Ten men (18-30 yr) fasted overnight and then were time blinded and made aware that they co uld request meals anytime. At first meal requests, volunteers consumed a pr eload; ad libitum meals were offered at subsequent requests. Postabsorptive ly, transient declines in blood glucose were associated with meal requests (chi(2) = 8.29). Subsequent meal requests occurred during "dynamic declines " in blood glucose after the peak induced by drink consumption (100%). Thes e meal requests took twice as long to occur after high-fat than after CHO p reloads (fat = 126 +/- 21, CHO = 65 +/- 15 min), consistent with difference s in interpolated 65-min satiety scores (fat = 38 +/-: 8.2, CHO = 16 +/- 4) . Postprandially, transient blood glucose declines were associated with mea l requests (chi(2) = 4.30). Spontaneous meal initiations were synchronized with transient and dynamic blood glucose declines. Synchronization of inter meal interval and dynamic declines related to higher satiating efficiency f rom high-fat preloads than from simple CHO preloads.