Less-energy-dense diets of low-income women in California are associated with higher energy-adjusted diet costs.
BACKGROUND
US-based studies are needed to estimate the relation, if any, between diet quality and estimated diet costs.


OBJECTIVE
We hypothesized that lower cost diets among low-income women in California would be energy dense but nutrient poor.


METHODS
Energy and nutrient intakes for 112 women aged 18-45 y living in California were obtained with a food-frequency instrument. Dietary energy density (in MJ/kg or kcal/g) and energy-adjusted diet costs (in $/10 MJ or $/2000 kcal) were calculated with local food prices. Tertile splits of energy density and energy cost were analyzed with one-factor analysis of variance.


RESULTS
Mean daily energy intake excluding all beverages was 7.1 MJ (1699 kcal), and mean dietary energy density was 6.5 kJ/kg (1.54 kcal/g). Lower dietary energy density was associated with significantly higher intakes of dietary fiber (P = 0.004), vitamin A (P < 0.001), and vitamin C (P < 0.001) and with significantly lower intakes of total fat (P = 0.003) and saturated fat (P < 0.001). Higher diet cost was associated with significantly lower dietary energy density (P < 0.001), total fat (P = 0.024), and saturated fat (P = 0.025) and with significantly higher intakes of vitamins A (P = 0.003) and C (P < 0.001). Each additional dollar in estimated diet costs was associated with a drop in energy density of 0.94 MJ/kg (0.225 kcal/g).


CONCLUSIONS
The finding that higher quality diets were more costly for these low-income women has implications for the food assistance and education programs of the US Department of Agriculture. Policy interventions may be required to allow low-income families in the United States to improve the quality of their diets given their food budget constraints.
Townsend
Marilyn S
MS
Nutrition Department, University of California, Davis, CA 95616, USA. mstownsend@ucdavis.edu
Aaron
Grant J
GJ
Monsivais
Pablo
P
Keim
Nancy L
NL
Drewnowski
Adam
A
D000293:Adolescent; D000328:Adult; D003365:Costs and Cost Analysis; D003430:Cross-Sectional Studies; D004032:Diet / Q000191:economics* / Q000592:standards*; D004041:Dietary Fats / Q000008:administration & dosage / Q000032:analysis; D002149:Energy Intake / Q000502:physiology*; D005260:Female; D005502:Food / Q000191:economics; D005504:Food Analysis; D006801:Humans; D018977:Micronutrients / Q000008:administration & dosage* / Q000032:analysis; D008875:Middle Aged; D018673:Nutrition Policy; D009753:Nutritive Value; D009765:Obesity / Q000453:epidemiology / Q000209:etiology; D011203:Poverty; D011632:Public Assistance; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D055815:Young Adult
D004041:Dietary Fats; D018977:Micronutrients