Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2020 Sep;21(9):e13044.
doi: 10.1111/obr.13044. Epub 2020 May 13.

Social norms and obesity prevalence: From cohort to system dynamics models

Loes Crielaard  1   2 , Pritha Dutta  3   4 , Rick Quax  2   5 , Mary Nicolaou  1   2 , Nadège Merabet  1   2 , Karien Stronks  1   2 , Peter M A Sloot  2   3   5
Affiliations
Review

Social norms and obesity prevalence: From cohort to system dynamics models

Loes Crielaard et al. Obes Rev. 2020 Sep.

Abstract

Group-level obesity can be seen as an emergent property of a complex system, consisting of feedback loops between individual body weight perception, individual weight-related behaviour and group-level social norms (a product of group-level 'normal' body mass index (BMI) and sociocultural 'ideal' BMI). As overweight becomes normal, the norm might be counteracting health awareness in shaping individual weight-related behaviour. System dynamics modelling facilitates understanding and simulating this system's emergent behaviour. We constructed six system dynamics models (SDMs) based on an expert-informed causal loop diagram and data from six sociocultural groups (Dutch, Moroccan and South-Asian Surinamese men and women). The SDMs served to explore the effect of three scenarios on group-level BMI: 'what if' weight-related behaviour were driven by (1) health awareness, (2) norms or (3) a combination of the two. Median BMI decreased approximately 50% and 30% less in scenarios 2 and 3, respectively, than in 1. In men, the drop in BMI was approximately two times larger in scenario 1 versus 3, whereas in women, the drop was approximately equal in these scenarios. This study indicates that the overweight norm in men holds group-level BMI close to overweight despite health awareness. Since norms are counteracting health awareness less strongly in women, other drivers of obesity must be more relevant.

Keywords: body weight perception; obesity; social norms; system dynamics modelling.

PubMed Disclaimer

Conflict of interest statement

No conflict of interest was declared.

Figures

FIGURE 1
FIGURE 1
Causal loop diagram (CLD) of the system of social norms regarding body weight perception and obesity prevalence. Variables are connected by arrows indicating causal links, where a plus indicates that an increase in the variable at the tail of the arrow constitutes an increase in the variable at the head of the arrow whereas a minus indicates that an increase in the variable at the tail constitutes a decrease in the variable at the head. Reinforcing feedback loops R1 and R2 and balancing feedback loop B1 are indicated with loop symbols
FIGURE 2
FIGURE 2
Body image scale
FIGURE 3
FIGURE 3
System dynamics model (SDM) mirroring the expert‐informed causal loop diagram (CLD) of the system of social norms regarding body weight perception and obesity prevalence. Variables (see Section 2.5) are connected by arrows indicating causal links. The stock is shown as a box (variable name displayed in bold, i.e. ‘Weight'), whereas flows are displayed as thick arrows (regulated by valves, variable names are underlined). Auxiliaries and constants are indicated in regular font and italics, respectively. Optimized parameters and constants based on initial values from the cohort data are marked with * and †, respectively
FIGURE 4
FIGURE 4
Change in group‐level body mass index (BMI) over time for three scenarios: ‘what if' weight‐related behaviour were driven (1) only by health awareness (red), (2) only by norms (blue) and (3) by health awareness and norms combined (green). The 95% confidence interval (details in Appendix S2.2) corresponding to each of these scenarios is shaded in red, blue and green, respectively
See this image and copyright information in PMC

References

    1. Burke MA, Heiland FW. Evolving societal norms of obesity. JAMA. 2018;319(3):221‐222. 10.1001/jama.2017.18947 - DOI - PubMed
    1. Madrigal H, Sánchez‐Villegas A, Martínez‐González M, et al. Underestimation of body mass index through perceived body image as compared to self‐reported body mass index in the European Union. Public Health. 2000;114(6):468‐473. 10.1038/sj.ph.1900702 - DOI - PubMed
    1. Halliwell E. Social Comparison Theory and Body Image. Vol 2 Elsevier Inc; 2012. 10.1016/b978-0-12-384925-0.00119-x - DOI
    1. Rutter H, Savona N, Glonti K, et al. The need for a complex systems model of evidence for public health. Lancet (London, England). 2017;390(10112):2602‐2604. 10.1016/S0140-6736(17)31267-9 - DOI - PubMed
    1. Rickles D, Hawe P, Shiell A. A simple guide to chaos and complexity. J Epidemiol Community Health. 2007;61(11):933‐937. 10.1136/jech.2006.054254 - DOI - PMC - PubMed

Publication types