The new study suggests that people with mood disorders rate are unable to discriminate between higher and lower fat foods – which may foster ‘unconscious eating’ of fatty foods in people with subclinical depression and anxiety.
Writing in PLoS One, the research team also revealed that that people with higher depression scores also rated bitter and sweet tastes as more intense.
Led by Dr Petra Platte the University of Wurzburg, Germany, the research team tested previous suggestions that the consumption of fat plays a major role in eating disorders by assessing whether the oral perceptions of fat and taste stimuli are altered in people are put in to a state of anxiety of mild depression.
“We observed that among the oral sensory stimuli examined, the ratings of fat were indiscriminant of fat concentration in the mildly subclinical depressed group, but only after the induction of positive or negative mood,” said Platte and her colleagues. “That is, people with mild subclinical depression were not able to rate fat intensities according to concentrations after either the positive or the negative mood induction.”
The team suggested that this inability to distinguish tastes may cause mildly depressed people to unconsciously eat more fatty foods.
“To our knowledge this is the first study to investigate both the effects of mood and affect on the perceptions of taste stimuli (quinine sulfate, sucrose, citric acid, and monopotassium glutamate) and dairy fat,” said Platte and her team.
The team assessedhow non-pathological levels of depression, anxiety and experimentally manipulated moods could affect participants' oral perceptions of fat and other taste stimuli like sweet, sour, bitter and umami flavours in 48 female and 32 male participants.
Participants in the study were scored for symptoms of depression and anxiety, and shown video clips of happy, sad and neutral scenes from movies to put them in a positive, negative or neutral mood.
Before and after watching the clips, they were asked to rate a series of liquids based on the intensity of flavour they experienced and were also asked to gauge the fat content in milk samples by mouth-feel.
Platte and her team found that participants with mild, subclinical signs of depression were unable to tell the difference between a high-fat and low-fat sample after watching a happy or sad movie clip - whereas they could distinguish between the two after watching a clip from a neutral film, as well as before they watched the movies.
These participants with higher depression scores also rated bitter and sweet tastes as being more intense after they watched the movie clips than they did before this mood-inducing exercise.
Platte said the findings could have potential implications for the unhealthy eating patterns seen in people with mild depression and mood disorders.
Source: PLoS One
Published online ahead of print, doi: doi:10.1371/journal.pone.0065006
Oral Perceptions of Fat and Taste Stimuli Are Modulated by Affect and Mood Induction
Authors: Petra Platte, Cornelia Herbert, Paul Pauli, Paul A. S. Breslin