Food Stores “Drive” Bariatric Surgery Outcomes?

Belief in the power of food stores and markets to shape outcomes in obesity runs deep. Perhaps it’s unshakable. But still, recent PR spin claiming that food stores “drive” bariatric surgery outcomes takes confusion of correlation with causality to new heights. In a press release from Ohio State University, the lead author of two new studies, Keely Pratt, says:

“Being in closer proximity to lower-quality stores predicted less weight loss, but being in closer proximity to higher-quality stores didn’t predict more weight loss. So the lower-quality stores were really driving poor outcomes.”

All this comes under a blunt headline: “Nearby food stores affect results after weight loss surgery.”

Interesting Methodology

In fairness to this pair of studies by Pratt et al, they provide interesting insights into neighborhood correlates for bariatric surgery outcomes in roughly eight hundred patients. But the number of correlates they investigated were limited, as they note:

“There are important economic factors likely not captured by this study that may contribute to selection of food stores available such as socioeconomic status and social deprivation index.”

And then there’s the fact that all of the patients come from a single county in Ohio. So, as the authors say, it is hardly representative of the broader population of bariatric surgery patients in the U.S.

Most important, though, is the simple fact that these analyses demonstrate a correlation – not a cause and effect relationship. So no, food stores do not “drive” bariatric surgery outcomes.

At Odds with Other Findings

Furthermore, the conclusion that food stores can drive bariatric surgery outcomes contradicts findings from another recent study. Jacqueline Murtha and colleagues examined a broader array of demographics and neighborhood factors. They found that none of the neighborhood factors, including the neighborhood food environment, explained variations in bariatric surgery outcomes:

“Patient characteristics rather than neighborhood-level social determinants and lifestyle factors were associated with weight loss after bariatric surgery in our cohort of bariatric surgery patients. Patients from socioeconomically deprived neighborhoods can achieve excellent weight loss after bariatric surgery.”

Looking Beyond the Mythology of Food Deserts

We would do well to get over the belief in food deserts as an important causal factor for obesity. Yes, people need access to wholesome, fresh foods, but access to food, by itself, has little effect on obesity prevalence. As Sarah Deemer, Arthur Owora, and David Allison wrote about a recent, careful study, the observed results “are far more consistent with trivial to zero effects than promising effects.”

Obesity medicine physician Fatima Cody Stanford tells us to look beyond the usual suspects for environmental influences on obesity:

“When we explore the social determinants of health, we must understand that these are far reaching and extend beyond grocery store proximity. We must fully examine stress, racism, the built environment, health care accessibility and affordability, and a host of other factors to fully understand the complexity of health outcomes with respect to bariatric surgery.”

In other words, get curiouser.

Click here and here for the studies by Pratt et al and here for the Murtha Study. For more on food deserts, click here.

Market in Algiers, painting by August Macke / WikiArt

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March 11, 2023