Using food price data to examine nutrition policy and social inequalities in diet

1. Using food price data to examine nutrition policy and social inequalities in diet Pablo Monsivais 24 Jan 2012

2. “Tell me what you eat and I will tell you what you are.” Brillat-Savarrin, 1826 Tell me what you spend and I will tell you how you eat.

3. Food Price Why it matters: • A key determinant of food choice, esp. for low income families • Food prices are positively associated with nutritional content • Rising prices for fruit & veg are associated with child weight gain • Social inequalities in diet • Price is a modifiable factor

4. Studying the cost of diets The data gap Dietary intake and health • Individual level Food prices and food spending • household or regional level • macroeconomic indicators

5. Studying the cost of diets Methods? Assess what was consumed and match with prevailing food prices Cade et al., 1997; Darmon et al., 2002; Schroeder et al., 2006; Drewnowski et al., 2007; Monsivais & Drewnowski, 2009 Townsend et al., 2009; Murakami et al., 2009; Bernstein et al., 2010, Rehm et al., 2011 Detailed assessment of what was purchased, what was consumed Monsivais et al., in preparation Monsivais et al., 2011; Monsivais & Johnson, 2011

6. Matching food consumed with food prices Diet cost is related to calories consumed Adapted from Monsivais, Aggarwal, Drewnowski, J Epi Com Health, 2010

7. Diet cost and diet quality Cost is related to the nutrient content of diets Potassium Added Sugars mg/day % calories I III V I III V diet cost group diet cost group Fiber Saturated Fats g/day % calories I III V I III V diet cost group diet cost group Means and 95% confidence intervals adjusted for energy intake, age, gender and race Adapted from Monsivais, Aggarwal, Drewnowski, J Epi Com Health, 2010

8. Disparities in diet quality Higher socioeconomic position is correlated with Higher intakes of micronutrients and fiber Lower intakes of fat Lower energy density of the diet Socioeconomic position obesity & chronic disease risk + diet quality −

9. Disparities in diet quality Diet cost follows a social gradient *** Diet Cost ($/day) ≤ $25 $25 – $49.9 $50 – $74.9 $75 – $99.9 ≥ $100 thousands/year Means and 95% CIs adjusted for energy, age, gender, race and household size Adapted from Monsivais, Aggarwal, Drewnowski, J Epi Com Health, 2010

10. Disparities in diet quality Diet cost follows a social gradient and can help account for the social gradient in nutrient consumption *** * Diet Cost ($/day) Potassium (mg) standard adjustments ≤ $25 $25 – $49.9 $50 – $74.9 $75 – $99.9 ≥ $100 ≤ $25 $25 – $49.9 $50 – $74.9 $75 – $99.9 ≥ $100 thousands/year thousands/year Means and 95% CIs adjusted for energy, age, gender, race and household size Adapted from Monsivais, Aggarwal, Drewnowski, J Epi Com Health, 2010

11. Disparities in diet quality Diet cost follows a social gradient and can help account for the social gradient in nutrient consumption *** standard adjustments + diet cost Diet Cost ($/day) Potassium (mg) n.s. standard adjustments ≤ $25 $25 – $49.9 $50 – $74.9 $75 – $99.9 ≥ $100 ≤ $25 $25 – $49.9 $50 – $74.9 $75 – $99.9 ≥ $100 thousands/year thousands/year Means and 95% CIs adjusted for energy, age, gender, race and household size Adapted from Monsivais, Aggarwal, Drewnowski, J Epi Com Health, 2010

12. Disparities in diet quality Diet cost follows a social gradient and can help account for the social gradient in nutrient consumption • Can account for between 36-76% of income related variation in diet quality. Aggarwal, Monsivais, Drewnowski, J Eur J Clin Nutr., 2011 socioeconomic position − obesity & chronic disease risk + diet quality −

13. Disparities in diet quality Diet cost follows a social gradient and can help account for the social gradient in nutrient consumption • Can account for between 36-76% of income related variation in diet quality. Aggarwal, Monsivais, Drewnowski, J Eur J Clin Nutr., 2011 + − socioeconomic position obesity & chronic disease risk diet quality + + − diet cost

14. Nutrition programs and policy Food spending can also partly account for beneficial effects of child nutrition programs + − nutrition program participation obesity & chronic disease risk diet quality + + − food spending Monsivais, Kirkpatrick, Johnson. J Am Diet Assoc., 2011 Monsivais, Johnson. Pub Health Nutr., 2011

15. What else can we do with diet cost data? • Cost of meeting dietary guidelines and other nutrition recommendations • Make dietary recommendations cost-sensitive • Minimum income recommendations (MIHL) • Project effects of food price changes on diet composition and diet quality

16. Emerging Issues in Public Health Nutrition • Rising food prices • Rising costs of living • Economic stress, insecurity

17. Summary • Food prices influence food choice, diet quality and health • Existing datasets are not well suited to study individual diet cost, diet quality and health • Diet cost data at the individual level can be used for policy-oriented nutrition research

18. Thank You