Impact of Portion Size and GDA Labelling on Soft Drinks in Cinemas
Author Information
Author(s): Willemijn M. Vermeer, Ingrid H. M. Steenhuis, Franca H. Leeuwis, Arjan E. R. Bos, Michiel de Boer, Jacob C. Seidell
Primary Institution: VU University Amsterdam
Hypothesis
Does portion size and caloric GDA labelling affect consumers' portion size choices and consumption of regular soft drinks?
Conclusion
Portion size and caloric GDA labelling were found to have no effect on soft drink intake.
Supporting Evidence
- Labelling did not increase the likelihood of choosing smaller portion sizes.
- Participants' self-reported impact of labelling showed no significant differences between conditions.
- A significant interaction effect was found between labelling and gender.
Takeaway
The study looked at whether labels on soft drink sizes help people choose smaller drinks, but they didn't really work.
Methodology
A field experiment with participants choosing from five soft drink sizes, comparing those with portion size and GDA labelling to those with only millilitre information.
Potential Biases
Self-reported data may suffer from social desirability bias.
Limitations
The study had a small sample size and relied on self-reported data, which may have biases.
Participant Demographics
Mean age of participants was 50.44 years, with 26.4% male and 33% overweight or obese.
Statistical Information
P-Value
p = .61 for portion size choice, p = .36 for large portion sizes.
Confidence Interval
CI: .25 - 2.25 for choosing smaller sizes, CI: .12 - 2.15 for choosing larger sizes.
Digital Object Identifier (DOI)
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