Odours can increase feelings of fullness, study suggests

By Will Chu

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The findings in this study show certain odours enhance the thick/creamy taste when paired together. ©iStock
The findings in this study show certain odours enhance the thick/creamy taste when paired together. ©iStock

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Using powerful food smells could increase feelings of fullness as a study has demonstrated the orosensory transfer of satiety expectations when certain odours are paired with specific foods.

The findings in this study demonstrate that certain odours enhanced the thick/creamy taste when paired together. Researchers found that the pairing increased both expected satiation and expected satiety.

A similar result also occurred when an odour paired with a sucrose drink boosted the drink’s sweet taste. Satiety expectations however were unaffected.

The study provides evidence of the sensory transfer of satiety expectations suggesting that certain odours can induce varying degrees of satiety even if the food may not be as tasty as other less filling foods.

Using satiety-associated odour cues could even be used to manipulate consumer satiety expectations.

Study procedure

almond
One of the odours looked at in the experiment was almond. ©iStock

Researchers from the University of Sussex began by enrolling 68 women and 12 men, aged 19–36.

These participants were asked to refrain from eating and to drink only water a couple of hours before the start of the experiment.

A baseline rating of appetite and mood was first determined. Here, participants filled in a mood rating questionnaire. The key ratings were for hunger and thirst, which were mixed with other moods such as nervousness, tiredness and alertness.

Participants then took part in a pre-training set of evaluations of the hedonic and sensory characteristics of five odours (chai, almond, caramel, fig and Earl Grey) and their expectations of how satiating these would be were also noted.

They then took turns in smelling each odour, rating how creamy, intense, novel, pleasant, sweet and thick that odour smelled. 

Next an odour-taste training method was used in which odours were experienced in the mouth paired either with sweetness alone (sweet: 10% sucrose), thickness alone (thick: a tara-gum solution) or these two combined (sweet/thick).

After this procedure, participants rated each stimuli (sweet, thick and sweet/thick). Participants were presented with two samples each of the three trained stimuli without any added odours, and rated their perception of thickness, creaminess, sweetness and liking for each stimulus.

“[The fact] that odours alone can acquire these expectations has potential value for product developers,” ​the study’s authors said.

“The addition of relevant sensory cues (thicker texture, creamy flavour note) may increase expected satiety which in turn should increase actual nutrient-induced satiety”

Smell and satiety links

cake, pie, serving size, portion , Copyright maramorosz
The link between satiety expectations and protion size has been well established. ©iStock/maramorosz

Desire has been identified as a key determinant in food choice and intake. However, individuals also take into account how filling a certain product will be, with particular attention paid to appetite and thirst.

These considerations can also have a large say in selecting portion sizes and how much food is consumed in a sitting.

The appeal of a food’s creaminess and thickness to the senses could lead to stronger expectations​ of how filling a product will be (expected satiation) and how well the product will subsequently suppress hunger (expected satiety).

“Creaminess was not a significant predictor of expectations when the product’s energy content was taken into account, presumably because this characteristic was also significantly associated with energy: the higher energy products were expected to be creamier. 

“This is in line with previous research linking perceived creaminess to a food’s fat,”​ the researchers said.

Source: Food Quality and Preference

Published online ahead of print, doi:10.1016/j.foodqual.2016.07.010

“That smells filling: Effects of pairings of odours with sweetness and thickness on odour perception and expected satiety.”

Authors: Martin Yeomans, Sophie Boakes et al.

Related topics Ingredients