Measuring the immeasurable? The challenges of researching mood and nutrition
The researchers from the University of Hull in the UK and Weill Cornell Medical College in Qatar said their review was an attempt to improve practices in the assessment and understanding of mood in nutrition research, which they said could be easily influenced by non-nutritive factors.
“Despite its importance as a reinforcer of ingestion, mood is hard to define and is inherently subjective. Consequently it is not feasible to produce a definitive procedure for assessing it.
“However, it is important to distinguish mood from emotion, and in nutrition research it is important to be aware of the distinction between protracted and transient mood, because the problems of assessing the two are quite different, and because eating and drinking are more likely to affect transient mood,” they wrote in the journal Nutrition Research Reviews.
They said research in this field largely focused on this longer term sense of mood, with rating systems developed to reflect this.
Meanwhile transient mood was far more difficult to measure, meaning assessments needed to be “theoretically considered, brief and administrable quickly, comprehensive, usable, fit for repetitive administration, and administrable under conditions where theoretically irrelevant cognitive factors that can influence mood rating have been considered and controlled”.
Spot the difference
The researchers defined emotions as “strong affective responses” that usually had visible behavioural effects like changes to facial expressions. Moods, however, did not necessarily manifest themselves in such a visible way.
Likewise they said it was important to distinguish ‘protracted mood’ as occurring over a period of hours or days, and therefore easier to assess by questionnaires, from the fluctuating ‘transient mood’.
This fluctuation could be problematic when using assessments that reported mood retrospectively, since to recall recent feelings could mean distortion or simply see the individuals forgetting.
As well as the rating system used, they said mood could be influenced by the psychological, social and physical environment around consumption.
And how does this nutrient make you feel?
Despite these challenges, they developed a ten-item questionnaire. This looked at the main dimensions of arousal (tired/energetic; restless/relaxed), the main emotions (happy/sad; angry/calm; anxious/composed; disgusted/satisfied), plus feelings relating to physical condition (hungry/full; thirsty/not thirsty; intoxicated/sober; ill/well).
Pain could also be added if relevant.
Source: Nutrition Research Reviews
Vol. 27, Iss. 02, p.p. 284–294, doi:10.1017/S0954422414000201
“How to measure mood in nutrition research”
Authors: R. Hammersley, M. Reid and S. L. Atkin