Benjamin Keep, PhD, JD | How I got tricked by this one weird trick - eating, the Delbeouf illusion, and meta-analyses @benjaminkeep | Uploaded October 2022 | Updated October 2024, 12 hours ago.
Research suggests that using small plates can reduce how much food you eat. This starts with a simple visual illusion, called the Delboeuf illusion. And then it gets more complicated from there.
00:00 Introduction
00:44 What is the Delboeuf illusion?
1:36 How the Delboeuf illusion can make us eat more food.
2:48 Was anything I said correct?
4:36 Potential explanations for why we eat more when served larger portions.
6:09 What this video is actually about.
6:49 The meta-analysis strikes back.
You can read more about Ben Goldacre here: en.wikipedia.org/wiki/Ben_Goldacre. I recommend his books and articles.
Sign up to my email newsletter, Avoiding Folly, here: benjaminkeep.com
References:
The original inspiration for this video came from:
Van Ittersum, K., & Wansink, B. (2012). Plate size and color suggestibility: The Delboeuf illusion’s bias on serving and eating behavior. Journal of Consumer Research, 39(2), 215-228. academic.oup.com/jcr/article-pdf/39/2/215/5081845/39-2-215.pdf
A meta-analysis looking at the small plate ➝ lower intake connection. And finding no consistent relationship.
Robinson, E., Nolan, S., Tudur‐Smith, C., Boyland, E. J., Harrold, J. A., Hardman, C. A., & Halford, J. C. (2014). Will smaller plates lead to smaller waists? A systematic review and meta‐analysis of the effect that experimental manipulation of dishware size has on energy consumption. Obesity Reviews, 15(10), 812-821. livrepository.liverpool.ac.uk/3009869/1/Robinson%20et%20al%20Obesity%20Reviews%20AAM.doc
And this piece raises questions about the size of the Delboeuf illusion for hungry people.
Zitron-Emanuel, N., & Ganel, T. (2018). Food deprivation reduces the susceptibility to size-contrast illusions. Appetite, 128, 138-144. sciencedirect.com/science/article/pii/S0195666318300011
How portion size effects caloric intake is still disputed. It seems like there's some anchoring involved (the initial portion suggests what is normal or appropriate) and bite size may play a role as well.
Herman, C. P., Polivy, J., Pliner, P., & Vartanian, L. R. (2015). Mechanisms underlying the portion-size effect. Physiology & Behavior, 144, 129-136. http://www2.psy.unsw.edu.au/Users/lvartanian/Publications/Herman,%20Polivy,%20Pliner,%20&%20Vartanian%20(2015).pdf
Burger, K. S., Fisher, J. O., & Johnson, S. L. (2011). Mechanisms behind the portion size effect: visibility and bite size. Obesity, 19(3), 546-551. onlinelibrary.wiley.com/doi/pdfdirect/10.1038/oby.2010.233
Marchiori, D., Papies, E. K., & Klein, O. (2014). The portion size effect on food intake. An anchoring and adjustment process?. Appetite, 81, 108-115. https://www.academia.edu/download/44357505/The_Portion_Size_Effect_on_Food_Intake_a20160403-22310-r0punj.pdf
Finally, this is my favorite meta-analysis, which DOES, in fact, suggest that smaller plates lead to smaller portion sizes and reduced consumption. It's still a "may" though. The effect seems quite vulnerable to user awareness. So if participants are aware that they're in a food study, researchers don't find an effect. Or if they're aware that they just changed their plates to reduce their consumption, you don't see an effect. But there is at least some suggestion that in the long-run, as your awareness of the changed plates fades, you do end up reducing your consumption.
Holden, S. S., Zlatevska, N., & Dubelaar, C. (2016). Whether smaller plates reduce consumption depends on who’s serving and who’s looking: a meta-analysis. Journal of the Association for Consumer Research, 1(1), 134-146. https://opus.lib.uts.edu.au/bitstream/10453/41448/1/2015003.email.pdf
Research suggests that using small plates can reduce how much food you eat. This starts with a simple visual illusion, called the Delboeuf illusion. And then it gets more complicated from there.
00:00 Introduction
00:44 What is the Delboeuf illusion?
1:36 How the Delboeuf illusion can make us eat more food.
2:48 Was anything I said correct?
4:36 Potential explanations for why we eat more when served larger portions.
6:09 What this video is actually about.
6:49 The meta-analysis strikes back.
You can read more about Ben Goldacre here: en.wikipedia.org/wiki/Ben_Goldacre. I recommend his books and articles.
Sign up to my email newsletter, Avoiding Folly, here: benjaminkeep.com
References:
The original inspiration for this video came from:
Van Ittersum, K., & Wansink, B. (2012). Plate size and color suggestibility: The Delboeuf illusion’s bias on serving and eating behavior. Journal of Consumer Research, 39(2), 215-228. academic.oup.com/jcr/article-pdf/39/2/215/5081845/39-2-215.pdf
A meta-analysis looking at the small plate ➝ lower intake connection. And finding no consistent relationship.
Robinson, E., Nolan, S., Tudur‐Smith, C., Boyland, E. J., Harrold, J. A., Hardman, C. A., & Halford, J. C. (2014). Will smaller plates lead to smaller waists? A systematic review and meta‐analysis of the effect that experimental manipulation of dishware size has on energy consumption. Obesity Reviews, 15(10), 812-821. livrepository.liverpool.ac.uk/3009869/1/Robinson%20et%20al%20Obesity%20Reviews%20AAM.doc
And this piece raises questions about the size of the Delboeuf illusion for hungry people.
Zitron-Emanuel, N., & Ganel, T. (2018). Food deprivation reduces the susceptibility to size-contrast illusions. Appetite, 128, 138-144. sciencedirect.com/science/article/pii/S0195666318300011
How portion size effects caloric intake is still disputed. It seems like there's some anchoring involved (the initial portion suggests what is normal or appropriate) and bite size may play a role as well.
Herman, C. P., Polivy, J., Pliner, P., & Vartanian, L. R. (2015). Mechanisms underlying the portion-size effect. Physiology & Behavior, 144, 129-136. http://www2.psy.unsw.edu.au/Users/lvartanian/Publications/Herman,%20Polivy,%20Pliner,%20&%20Vartanian%20(2015).pdf
Burger, K. S., Fisher, J. O., & Johnson, S. L. (2011). Mechanisms behind the portion size effect: visibility and bite size. Obesity, 19(3), 546-551. onlinelibrary.wiley.com/doi/pdfdirect/10.1038/oby.2010.233
Marchiori, D., Papies, E. K., & Klein, O. (2014). The portion size effect on food intake. An anchoring and adjustment process?. Appetite, 81, 108-115. https://www.academia.edu/download/44357505/The_Portion_Size_Effect_on_Food_Intake_a20160403-22310-r0punj.pdf
Finally, this is my favorite meta-analysis, which DOES, in fact, suggest that smaller plates lead to smaller portion sizes and reduced consumption. It's still a "may" though. The effect seems quite vulnerable to user awareness. So if participants are aware that they're in a food study, researchers don't find an effect. Or if they're aware that they just changed their plates to reduce their consumption, you don't see an effect. But there is at least some suggestion that in the long-run, as your awareness of the changed plates fades, you do end up reducing your consumption.
Holden, S. S., Zlatevska, N., & Dubelaar, C. (2016). Whether smaller plates reduce consumption depends on who’s serving and who’s looking: a meta-analysis. Journal of the Association for Consumer Research, 1(1), 134-146. https://opus.lib.uts.edu.au/bitstream/10453/41448/1/2015003.email.pdf
