Effect of sniffing and odour concentration on appetite, sensory-specific appetite, food choice and food intake

There is a need from industry for scientific knowledge on how odours influence
appetite responses, food intake and food choice to support product development.
Several studies found that the appetite for a smelled food increased more than
the appetite for foods that were not smelled. The latter is named
sensory-specific appetite (SSA). Data from our previous study SpitOut do not
correspond with the data from the study that was executed by Rolls [7].
Although participants of both studies were exposed to orthonasal odour (from
the outside world through the nose), our method differed from the method that
Rolls used: 1. In the study by Rolls participants actively sniffed a cup that
was filled with smashed bananas, while the participants in our study smelled
the odours passively, i.e. the participants sat in a room that was filled with
odour. 2. Moreover, the concentration of the smashed bananas may have been
different from the concentration that we had in the test room. Furthermore, it
may be that *natural* odours evoke stronger SSA responses than *synthetical*
odours.

To investigate the effect of sniffing , odour concentration and 'naturalness'
on appetite, sensory-specific appetite, food choice and food intake.

A parallel intervention study with 2 groups will be conducted: group *passive*
and group 'active. Participants will be randomly assigned to one of the groups.
Both groups will be exposed to six conditions.
Group 'passive' will be exposed to two odours (banana and meat) and three
different concentration conditions: no-odour, low odour concentration and high
odour concentration.
Group *active* will be asked to intensely sniff a cup that is filled with
either no odour (duplo), a synthetical odour (banana or meat), or real food
(smashed banana or steamed meat).
Participants are expected in the lab for six times around lunch time, with a
wash-out time of preferably one week but at least four days. During every
visit, the participants will be exposed to one test condition. During each
session we will measure appetite, sensory-specific appetite, sensory-specific
satiation, food choice and food intake.

exposure to odours by passive or active smelling

The study is non-therapeutic to the participant. The risk associated with
participation is negligible.
Compared to other studies the burden can be considered as low