Objective: Perceptions of a healthy body weight may be influenced by social norms within a social network. This study tested the hypothesis that social network body size is associated with body size norms in South Asian adults from the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study.
Methods: South Asian adults (n=700) were asked to list their personal social network members, defined as the “people who you regularly talk with about things that are important to you,” at the social network ancillary study examination (2014-2017). Participants’ perceptions of their network members’ body sizes, their own body size (self-body size), and a healthy body size (body size norm) for men and women were assessed using the Stunkard 9-figure scale. The Stunkard scale is a silhouette figure rating scale consisting of 9 male and 9 female figures of increasing body size (range 1-9). Participants’ height and weight were measured, and body mass index (BMI) was calculated. The average body size of network members was the main independent variable. Body size norm was the dependent variable in a regression model that controlled for age, sex, gender of Stunkard figure, cultural identity, self-body size, participants’ measured BMI, and social network size. A random intercept term was included at the participant level to account for clustering of male and female body size norms within participants.
Results: Participants’ average age was 59 years (SD+/-9 years) and 43% were female. The average body size norm for male and female Stunkard images was 3.6 (SD+/-1.0) and 3.4 (SD+/-0.8), respectively. Participants’ average self-body size was 4.7 (SD+/-1.5). There were 2,991 social network members identified (mean number of network members=4, SD=1), and the majority (70%) were kin. The average network body size was 3.9 (SD +/-1.1). For every unit increase in their networks’ average body size, participants’ perceptions of body size norms increased 0.31 points on the Stunkard scale (p<0.01; 95% CI: 0.25, 0.36), independent of self-body size and BMI. Perception of a healthy body size norm was 0.25 points lower for female Stunkard figures than for male figures (p<.01; 95% CI: -0.30, -0.20).
Conclusions: Having social network members with larger body sizes was associated with a higher body size norm in South Asian adults. Norms for female body images were smaller than for male images. Long-term follow-up of the MASALA cohort will determine if network members’ body size and body size norms are associated with weight change and weight-control behaviors in South Asians.