MyFitnessPal Study Shows Where You Live Can Affect Your Diet Quality

Researchers are finding new ways to study the relationship between food environment and dietary health.

Previous studies have linked food deserts to increased risk of heart disease and food swamps to higher rates of obesity. But there are limitations when it comes to studying and implementing effective policies to expand food and nutrition access. Opening new grocery stores in food deserts doesn’t always offer the solutions researchers might expect.

For example, a 2014 report from the National Institutes of Health found that bringing a new grocery store to a low-income, low-food access neighborhood in Philadelphia didn’t significantly change diet quality for the residents.

“It is fundamentally challenging to disentangle the effects of the environment on behaviors such as healthy eating,” Tim Althoff, PhD, an assistant professor of computer science and engineering at the University of Washington, told Verywell.

Althoff said that diet studies are typically restricted to “small sample sizes, single locations, and non-uniform design across studies,” which have led to mixed results on the impact of food environment.

In response, his team developed strategies to use diet-tracking apps to study eating habits on a larger scale. Althoff and his team of researchers recently published findings from their analysis of over 1 million MyFitnessPal users across more than 9,800 U.S. zip codes in Nature Communications. MyFitnessPal is one of the most widely used mobile apps for weight loss and calorie count.

“With this study, we wanted to leverage such anonymized data to better understand diets in the U.S. and what influences those diets,” Althoff said.

Specifically, the researchers were interested in studying how built environments affect different dietary and health markers. The findings showed that higher access to grocery stores, lower access to fast food, higher income and college education are independently associated with higher consumption of fresh produce and lower likelihood of being classified as overweight or obese, Althoff said.

While these findings are not particularly surprising, he added, they are important markers for policymakers. When the data was separated by zip code, though, the association between grocery store access and increased consumption of fruits and vegetables increases significantly in predominantly Hispanic and Black communities.

“They say that your zip code is more powerful than your genetic code,” Lauri Wright, PhD, RDN, FAND, director of the Center for Nutrition & Food Security at the University of North Florida, who is not affiliated with the study, told Verywell. “Probably only about 20% of diseases come from genetics, the rest is our environment, and environments are not created equal.”

How Social Determinants Impact Diet Quality

Experts call these environmental factors “social determinants of health.” Examples of these factors include racism, safe housing, education quality, job opportunities, and pollution.

According to the study, in predominantly Black neighborhoods, higher income was not associated with healthier eating patterns.

Since this was a cross-sectional study, the researchers cannot explain the causality in their findings. But the authors suggested that the gaps may have to do with the “diminishing return hypothesis,” which suggests that Black Americans do not have receive the same health protections even if they achieve a higher socioeconomic status as their White counterparts.

Diet quality is just one example where health disparities are seen. A 2018 Duke University report examining infant mortality gap found that Black women with higher education have a higher infant mortality rate than White women who never finished high school. The Duke researchers pointed to the stress Black women experience from facing years of systemic racism as a contributing factor for the stark disparities.

A buildup of environmental stress caused by social determinants of health is sometimes more influential than an individual’s achievements. The stress is especially damaging for people living in food-insecure environments, Wright said.

“It takes a toll. It’s almost like a chronic disease in and of itself,” she said.

Find Individualized Solutions

For people living in food-insecure communities, these social determinants of health may feel out of their control. The researchers hope that their study can help policymakers create meaningful public health solutions.

As more studies continue to illuminate the need for individualized solutions, researchers say it’s essential to address public health challenges at a community level.

“People assume that if we eliminate food deserts, that will automatically lead to healthier eating, and that a higher income and a higher degree lead to a higher quality diet. These assumptions are, indeed, borne out by the data at the whole population level,” Jenna Hua, PhD, MPH, RD, a former postdoctoral fellow at Stanford University School of Medicine and coauthor of the study, said in a statement.

“Diet is a complex issue,” Hua said. “While policies aimed at improving food access, economic opportunity and education can and do support healthy eating, our findings strongly suggest that we need to tailor interventions to communities rather than pursuing a one-size-fits-all approach.”