'Hedonic hunger' refers to the desire to eat for pleasure, and to enjoy
the taste, rather than to restore the body''s energy needs,"says
Palmiero Monteleone, MD, of the University of Naples SUN in Italy and
lead author of this study. "For example, desiring and eating a piece of
cake even after a satiating meal is consumption driven by pleasure and
not by energy deprivation. The physiological process underlying hedonic
eating is not fully understood, but it is likely that endogenous
substances regulating reward mechanisms like the hormone ghrelin and
chemical compounds such as 2-arachidonoylglycerol (2-AG) are involved."
In this study, researchers assessed eight satiated healthy adults, aged
21-33 years, feeding them each their personal favorite food and, later, a
less-palatable food of equal caloric and nutrient value. Researchers
periodically measured 2-AG and ghrelin levels. The plasma levels of
ghrelin and 2-AG increased during hedonic eating, with the favorite
foods, but not with non-hedonic eating. This increase suggests an
activation of the chemical reward system, which overrides the body''s
signal that enough has been eaten to restore energy.
"Hedonic hunger may powerfully stimulate overeating in an environment
where highly palatable foods are omnipresent, and contribute to the
surge in obesity,"says Monteleone. "Understanding the physiological
mechanisms underlying this eating behaviour may shed some light on the
obesity epidemic. Further research should confirm and extend our results
to patients with obesity or with other eating disorders in order to
better understand the phenomenon of hedonic eating."