A review of quantitative studies examining the relationship between religion and body weight found that religiosity was consistently associated with higher body weight in cross-sectional analyses, with the relationship more pronounced in multivariate examinations, according to study findings reported in Obesity Reviews.
In a review of 85 studies, researchers did not observe consistent associations between religious affiliation and body weight; however, several studies pointed to a trend of lower body weight among Seventh-day Adventists when compared with non-Seventh-day Adventists.
“Religion is an influential social institution that has multifaceted relationships with many aspects of people’s lives, including their eating, physical activity and health,” Karen Hye-cheon Kim Yeary, PhD, of the University of Arkansas for Medical Sciences in Little Rock, and colleagues wrote. “Obesity and body weight have emerged as a salient health concern in the late 20th and early 21st centuries, and religion has increasingly been examined in relationship to body weight. Body weight has been primarily framed as a health issue, but it is also an important psychosocial identity.”
Yeary and colleagues analyzed data from 85 studies that quantitatively examined the religion-body weight relationship over 50 years; most included studies (62%) were published after 2010; median year of publication was 2008. Sample sizes ranged from 21 to more than 150,000 (median sample size, 1,682); 53% of studies were conducted in the United States, and 89% were cross-sectional. Among included studies, 56% examined religious affiliation and 61% examined religiosity, with 18% studying both.
In more than half of studies, researchers found that religious affiliation was associated with body weight, but these associations were attenuated in analyses that controlled for demographic characteristics when compared with bivariate analyses.
“Overall, among all of the religious affiliation studies, the substantive findings are very difficult to compare because religious affiliation was categorized in different ways across studies,” the researchers wrote.
However, in four studies examining bivariate associations between Seventh-day Adventists and body weight, three of four studies found that Seventh-day Adventists had a lower body weight when compared with non-Seventh-day Adventists. In one Australian study comparing measured body weights of Seventh-day Adventists (n = 779) with patients from a general practitioner clinic (n = 7,115) and volunteers (n = 9,825), researchers observed lower body weights in the Seventh-day Adventist sample. In an intervention study of 7,172 North American adults, researchers reported a lower mean BMI in Seventh-day Adventists (mean, 30.1 kg/m²) compared with non-Seventh-day Adventists (mean, 31.48 kg/m²) in bivariate analyses at baseline.
“Seventh-day Adventist doctrine espouses lacto-vegetarian diets, which may be protective against obesity in this population,” the researchers wrote. “However, it is unclear whether the totality of Seventh-day Adventist adherents — including those who do not adhere to vegetarian diets — have lower body weights than non-Seventh-day Adventists. Vegetarians among Seventh-day Adventist adherents may be responsible for the lower body weights of Seventh-day Adventists.”
In studies examining religiosity, researchers found that religious involvement was associated with higher body weight in most studies; however, the magnitude of the relationship was difficult to quantify due to varying descriptions of religiosity and body weight, the researchers wrote. Among studies that reported associations that adjusted for multiple confounders and utilized randomly selected, nationally representative samples, religious practice or attendance increased BMI by a mean of 0.07 kg/m² and 0.31 kg/m².
“Although the magnitude of religiosity’s relationship with body weight may be a small effect size at best, religiosity as a social factor in obesity is similar to other social factors that predict variations in body weight,” the researchers wrote.
“I think religion and spirituality is a relevant topic to consider for clinicians in general, but at this point the current evidence does not warrant specific discussions of religion and spirituality in weight and metabolic health,” Yeary told Endocrine Today. “More rigorous, longitudinal studies that utilize comprehensive measures of religion and spirituality are needed to move this work forward.” – by Regina Schaffer
Disclosure: The authors report no relevant financial disclosures.