A person's ability to follow a healthy diet is heavily influenced by their neighbourhood's food environment and their income level, a new study has found. The research highlights a significant gap in dietary adherence between different socioeconomic groups, pointing to the urgent need for more personalised nutrition advice.
The Study: Simulating Diets Across Los Angeles Neighbourhoods
Researchers aimed to understand how difficult it would be for people to maintain the combined Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diet, known as MED-DASH, compared to simply defaulting to the Typical American Diet (TAD). The study, published in the journal Health & Place, used advanced geospatially explicit Agent-Based Models (ABMs) to simulate three distinct neighbourhoods in Los Angeles, California.
The virtual neighbourhoods represented a cross-section of socioeconomic statuses: Boyle Heights (lower-income), Inglewood (middle-income), and Santa Monica (higher-income). The study tested how well virtual residents, represented by computational agents, could stick to the MED-DASH diet within their specific local food environment.
Key Findings: A Stark Income-Based Divide
The results revealed a clear and concerning trend. Average adherence to the healthy MED-DASH diet was lowest in the lower-income neighbourhood at 57.43% (95% CI: 55.67%–59.19%). It improved in the middle-income area to 62.39% (95% CI: 60.59–64.19%), and was highest in the wealthier neighbourhood at 68.02% (95% CI: 66.21–69.82%).
Perhaps the most telling finding was the impact of cost. When researchers simulated a 50% reduction in the average price of MED-DASH foods, adherence jumped significantly. The increase was most dramatic in the lower-income area, soaring by 17.24%. The middle-income neighbourhood saw a 10.36% rise, while the higher-income area had a modest 1.88% increase.
Expert Calls for Precision Nutrition and Environmental Focus
The study's authors strongly advocate for a shift in how dietary guidance is provided. Jessie Heneghan, the study's lead author and a Senior Analyst at PHICOR, emphasised that clinicians and nutrition programs must account for where people live, the nearby food outlets, and the cost of healthy food when designing interventions.
Co-author Kayla de la Haye, director of the USC Food Systems Institute in Los Angeles, stressed the critical need for precision nutrition. She highlighted the alarming statistic that fewer than 2% of Americans consume a diet ideal for good health, underscoring that one-size-fits-all dietary advice is failing the population.
The overarching conclusion is clear: for dietary recommendations and precision nutrition approaches to be effective, they must seriously consider the surrounding food environment and find concrete ways to make healthier diets more affordable and accessible for everyone, regardless of their postal code or paycheck.
