The contribution of three components of nutrition knowledge to socio-economic differences in food purchasing choices.
OBJECTIVE
To assess socio-economic differences in three components of nutrition knowledge, i.e. knowledge of (i) the relationship between diet and disease, (ii) the nutrient content of foods and (iii) dietary guideline recommendations; furthermore, to determine if socio-economic differences in nutrition knowledge contribute to inequalities in food purchasing choices.


METHODS
The cross-sectional study considered household food purchasing, nutrition knowledge, socio-economic and demographic information. Household food purchasing choices were summarised by three indices, based on self-reported purchasing of sixteen groceries, nineteen fruits and twenty-one vegetables. Socio-economic position (SEP) was measured by household income and education. Associations between SEP, nutrition knowledge and food purchasing were examined using general linear models adjusted for age, gender, household type and household size.


METHODS
Brisbane, Australia in 2000.


METHODS
Main household food shoppers (n 1003, response rate 66·4 %), located in fifty small areas (Census Collectors Districts).


RESULTS
Shoppers in households of low SEP made food purchasing choices that were less consistent with dietary guideline recommendations: they were more likely to purchase grocery foods comparatively higher in salt, sugar and fat, and lower in fibre, and they purchased a narrower range of fruits and vegetables. Those of higher SEP had greater nutrition knowledge and this factor attenuated most associations between SEP and food purchasing choices. Among nutrition knowledge factors, knowledge of the relationship between diet and disease made the greatest and most consistent contribution to explaining socio-economic differences in food purchasing.


CONCLUSIONS
Addressing inequalities in nutrition knowledge is likely to reduce socio-economic differences in compliance with dietary guidelines. Improving knowledge of the relationship between diet and disease appears to be a particularly relevant focus for health promotion aimed to reduce socio-economic differences in diet and related health inequalities.
School of Public Health and Social Work,Queensland University of Technology,Victoria Park Road,Kelvin Grove,Brisbane,QLD 4059,Australia.
Loretta
L
McKinnon
School of Public Health and Social Work,Queensland University of Technology,Victoria Park Road,Kelvin Grove,Brisbane,QLD 4059,Australia.
Katrina
K
Giskes
School of Public Health and Social Work,Queensland University of Technology,Victoria Park Road,Kelvin Grove,Brisbane,QLD 4059,Australia.
Gavin
G
Turrell
D000328:Adult; D000368:Aged; D001315:Australia; D002755:Choice Behavior; D003258:Consumer Behavior; D003430:Cross-Sectional Studies; D004032:Diet; D004522:Educational Status; D005191:Family Characteristics; D005247:Feeding Behavior; D005260:Female; D005518:Food Preferences; D006262:Health; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D007182:Income; D008297:Male; D008875:Middle Aged; D018673:Nutrition Policy; D009753:Nutritive Value; D012923:Social Class; D055815:Young Adult