Pairing ingested nutrients with odours has other important
consequences, particularly in relation to motivation
to consume. Thus, pairing novel odours with glutamate in
soup increased liking for those odours, but in addition
exposure to the flavour following conditioning also increased
feelings of hunger and consumption of the soup,
relative to simple repeated exposure to the soup . This
suggests a mechanism for the development of food ‘wanting’,
a distinct construct from ‘liking’ that has been
explored in terms of both distinct neural and motivational
substrates . Wanting reflects a drive to consume,
the effects of which can be observed in eating that is
independent of energy needs. In particular, wanting can
be triggered by sensory cues — odours, visual or auditory
cues — that have been associated with nutrient learning.
Examples of this can be found in research showing
consumption of a food in response to cues can occur even
after consuming the same food to satiation . As such,
there is obvious relevance to our understanding of the
aetiology of obesity.