Similar
fructose increases have been reported in healthy volunteers who consumed
fructose loads between 0.5 and 0.75 g / kg34 and in individuals who consumed
fructose - sweetened beverages with mixed meals.35 Leptin and ghrelin
levels were indistinguishable following acute ingestion
of glucose or
fructose, a finding possibly attributable to the short time interval
of observation; leptin
levels typically change 4 to 6 hours after glucose administration.36 Although
fructose was previously reported to be less effective than glucose in suppressing ghrelin, such differences may be attributable to the different conditions and timing
of ghrelin measurements.10 Little is known about the acute PYY response to
fructose ingestion compared with glucose ingestion, although 1 study in rats found
higher rather than lower PYY
levels after 24 hours
of glucose but not
fructose feeding.11 Whether such disparities are related to study design or species differences remains uncertain.