Page 86 - IJPS-8-1

International Journal of
Population Studies Urbanization and body weight

individuals’ body weight was found to be largely driven a shorter study period during which consistent measures
by between-community difference. This finding holds for are available to decompose the associations between
both men and women and is robust against the choice of urbanization and these intermediate outcomes.
disaggregation method or body weight measure. In other Despite these limitations, findings from this study
words, contrary to the conventional theory, little evidence highlight complex patterns of body weight changes in
supports that an increase in the level of urbanization relation to urbanization as the Chinese society transitions
within a community was related to weight gain among
its residents. The observed positive association between from an old era of poverty and under-nutrition to a new
urbanization and body weight status was heavily inferred one of affluence and over-nutrition. The findings also
from disparities between individuals living in different challenge the adequacy of the simple conventional model
communities that differed in their baseline and trajectory of community effects on health (Averett & Korenman,
of urbanization. 1999; Entwisle, 2007). Understanding risks for obesity in
adults depends not only on whether they live in urbanized
The lack of association between within-community communities but also on how obesogenic environments
urbanization and weight gain might reflect insufficient evolve as a result of human activities. In terms of policy
statistical power. For example, as evident in Figure 3 and in implications, the findings suggest that limited public health
Supplementary File Table S3, the cross-sectional between- resources to address the rising prevalence of obesity should
community variation in the urbanicity index score at any not be evenly distributed but targeted at city and town
time point was considerably larger than the longitudinal communities where the level of urbanization continues to
within-community variation over any two consecutive be high and migrants from rural areas are about to adopt
waves of the CHNS. As a result, the CHNS data provided new lifestyles.
greater statistical power for researchers to detect potential
between-community effect than within-community effect. Acknowledgments
In essence, this is similar to the drawback of fixed-effects
models being less efficient than random-effects models of None.
longitudinal data. Funding
To be comparable with previous research, the present
study did not disentangle the multiple dimensions of This study was supported by the Lieberthal Rogel Center for
urbanization. The urbanicity index provides a single Chinese Studies at the University of Michigan under a faculty
composite measure of 12 distinct aspects of urbanization research grant and City University of New York – Queens
and, hence, does not allow researchers to identify the College under a Cycle 50 PSC-CUNY Research Award
heterogeneity in the process of urbanization that may have (TRADA-50-116). The CHNS data collection has been
diverse implications for people’s weight gain. For example, funded by the National Institute for Health (NIH), the
when a village develops into a town, not only would its Eunice Kennedy Shriver National Institute of Child Health
transportation infrastructure and food environment and Human Development (NICHD) for R01 HD30880,
change substantially but also more importantly, new urban National Institute on Aging (NIA) for R01 AG065357,
social and economic structures would be established National Institute of Diabetes and Digestive and Kidney
in place of the old rural ones. Agricultural work would Diseases (NIDDK) for R01DK104371 and R01HL108427,
be replaced by manufacture or service industry, and a and the NIH Fogarty grant D43 TW009077 since 1989.
physically active lifestyle might be replaced by a sedentary
lifestyle, making villagers more susceptible to changes in Conflict of interest
body weight status than, say, city dwellers whose lifestyles No conflicts of interest were reported by the author.
would change less drastically as their urban community
experiences such gradual changes as the opening of a new Author contributions
supermarket or subway station. Therefore, future research
should develop and test theories that identify specific This is a sole-authored study.
aspects of urbanization related to weight gain. Furthermore, Ethics approval and consent to participate
the present study does not examine intermediate diet and
physical activity outcomes that lie in the pathway to weight This study does not involve human subjects as defined
gain. However, the CHNS has made some changes in by CUNY Human Research Protection Program (HRPP)
questionnaire design related to self-reported measures of because it only involves analysis of publicly available,
diet and physical activities, making longitudinal analysis secondary survey data. Therefore, this study does not
difficult. Future research using the CHNS data may specify require CUNY HRPP or IRB review.

Volume 8 Issue 1 (2022) 80 https://doi.org/10.36922/ijps.v8i1.334