Does diet cost mediate the relation between socioeconomic position and diet quality?

Area of Science:

• Public Health
• Nutritional Epidemiology
• Socioeconomic Determinants of Health

Background:

• Socioeconomic status (SES) significantly influences diet quality.
• Existing research confirms disparities in dietary patterns based on income and education.

Purpose of the Study:

• To investigate if diet cost mediates the relationship between socioeconomic position and diet quality.
• To test the hypothesis that lower diet quality among lower SES groups is partly explained by higher food costs.

Main Methods:

• Cross-sectional Seattle Obesity Study (S.O.S) involving 1266 adults.
• Dietary intake assessed via food frequency questionnaire (FFQ); diet quality measured by energy density and mean adequacy ratio (MAR).
• Diet cost calculated using retail prices; socioeconomic position indicated by income and education.

Main Results:

• Higher income and education were linked to lower energy density and higher MAR scores.
• Increased income and education also correlated with higher diet costs.
• Diet cost significantly mediated the association between income and diet quality, with education moderating this pathway.

Conclusions:

• Diet cost is a significant factor explaining the social gradient in diet quality.
• Interventions to improve diet quality in lower SES populations should consider food pricing and affordability alongside nutrition education.