Related Experiment Video
Updated: May 8, 2026
07:07
Errors as a Means of Reducing Impulsive Food Choice
Published on: June 5, 2016
Underestimating calorie content when healthy foods are present: an averaging effect or a reference-dependent
Suzanna E Forwood1, Amy Ahern, Gareth J Hollands
1Behaviour and Health Research Unit, Department for Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom. Sef26@cam.ac.uk
Plos One
|August 23, 2013
Summary
The negative calorie illusion, where unhealthy foods seem less caloric next to healthy options, was replicated using a reference food. This effect stems from contrast, not averaging, and is influenced by viewing order.
Area of Science:
- Behavioral Economics
- Cognitive Psychology
- Food Science
Background:
- The negative calorie illusion suggests unhealthy foods are perceived as less caloric when paired with healthy items.
- This effect was previously attributed to averaging perceived healthiness and calorie content.
- The current study investigated the validity and underlying mechanisms of this illusion.
Purpose of the Study:
- To replicate and extend findings on the negative calorie illusion.
- To test the mediating role of perceived healthiness on calorie estimates.
- To explore the influence of reference points and viewing order on calorie perception.
Main Methods:
- Three online studies were conducted involving participants estimating food calorie content.
- Healthiness ratings of foods were assessed alongside calorie estimations.
- A specific procedure using a reference food was employed in the final study.
Main Results:
- The negative calorie illusion was not replicated in the first two studies.
- A negative calorie illusion was observed in the final study when a reference food was used.
- No evidence supported perceived healthiness as a mediator for calorie estimates.
Conclusions:
- The negative calorie illusion is dependent on contrast with a reference food, not an averaging effect.
- Findings support a reference-dependent anchoring and adjustment heuristic.
- The order of food presentation significantly impacts calorie evaluation.
Related Concept Videos
01:25The Anchoring-and-Adjustment Heuristic
In order to make good decisions, we use our knowledge and our reasoning. Often, this knowledge and reasoning is sound and solid. However, sometimes, we are swayed by biases or by others manipulating a situation. For example, let’s say you and three friends wanted to rent a house and had a combined target budget of $1,600. The realtor shows you only very run-down houses for $1,600 and then shows you a very nice house for $2,000. Might you ask each person to pay more in rent to get the $2,000...
01:08The Availability Heuristic
A heuristic is a general problem-solving framework (Tversky & Kahneman, 1974). You can think of these as mental shortcuts that are used to solve problems. Different types of heuristics are used in different types of situations, and the impulse to use a heuristic occurs when one of five conditions is met (Pratkanis, 1989):
01:31Confirmation Biases
The confirmation bias is the tendency to focus on information that confirms our existing beliefs and ignore information that is inconsistent with our expectations. For example, if you think that your professor is not very nice, you notice all of the instances of rude behavior exhibited by the professor while ignoring the countless pleasant interactions he is involved in on a daily basis. Have you ever fallen prey to the confirmation bias, either as the source or target of such bias?
01:52Regression Toward the Mean
Regression toward the mean (“RTM”) is a phenomenon in which extremely high or low values—for example, and individual’s blood pressure at a particular moment—appear closer to a group’s average upon remeasuring. Although this statistical peculiarity is the result of random error and chance, it has been problematic across various medical, scientific, financial and psychological applications. In particular, RTM, if not taken into account, can interfere when researchers try to extrapolate results...
00:57Weighted Mean
While taking the arithmetic, geometric, or harmonic mean of a sample data set, equal importance is assigned to all the data points. However, all the values may not always be equally important in some data sets. An intrinsic bias might make it more important to give more weightage to specific values over others.
For example, consider the number of goals scored in the matches of a tournament. While computing the average number of goals scored in the tournament, it may be more important to...
For example, consider the number of goals scored in the matches of a tournament. While computing the average number of goals scored in the tournament, it may be more important to...
01:19Energy Balance
The human body gets energy from the three macronutrients: carbohydrates, proteins, and fats. Energy is released when the chemical bonds in the organic compounds present in the food are broken down. The energy content of food is measured in kilocalories (kcal), defined as the amount of heat required to raise the temperature of one kilogram of water by one degree Celsius. This value is determined by measuring the temperature change of the water surrounding a calorimeter after the complete...