Food security in New Zealand: The relationship between food security, ethnicity and body weight status
Food security and body weight status are each a growing area of concern for many New Zealanders. Food security is characterized as having at all times enough nutritionally adequate food for a healthy life. It has been associated with many health outcomes, ranging from nutrient intake, to effect on weight status and mental and social wellbeing. The Adult Nutrition Survey 2008/09 allows a unique opportunity to examine household food security status within New Zealand and its relationship to body weight status and nutrient intake on a nationally representative sample of New Zealanders. Data were analysed from the Adult Nutrition Survey 2008/09 with an overall sample size used in these analyses of 4441. Household food security was determined by responses to eight statements that were collapsed into three categories: fully/almost fully food secure; moderately food secure; and low food security status. Body weight status was determined by body mass index (BMI weight/height2) and obesity (BMI≥30kg/m2). Nutrient intakes of participants were determined during a home visit using an interviewer assisted multi-pass 24-hour recall. Multivariate analysis was used to explore the relationship between food security status and BMI/obesity and nutrient intakes adjusted for age, ethnicity, sex, income, education, New Zealand Deprivation Index 2006 and household size. Survey weights were used in all analyses. In the New Zealand population 59.1% were fully/almost fully food secure, 33.8% moderately food secure and 7.1% were of low food security status. Only 34.8% of Maori and 26% of Pacific were identified as being of fully/almost fully food secure compared with 64.2% of New Zealand European and Others (NZEO). The proportion of New Zealanders who identified as having fully/almost full food security has also significantly declined from 76% in the National Nutrition Survey 1997 to 59% in the Adult Nutrition Survey 2008/09 (P<0.05). Results from multivariate analysis indicate that lack of food security is associated with a higher body weight status with the relationship strongest in females. Compared with females of fully/almost fully food security status, females of moderate food security status had a higher BMI (28.3 kg/m2 cf 29.4 kg/m2, P<0.05) while low food secure females had a higher likelihood of obesity (OR=1.87). Compared with fully/almost fully food secure females those of moderate food security had a higher BMI among NZEO (26.8 kg/m2 cf 27.8 kg/m2, P<0.05) and Maori (30.3 kg/m2 cf 32.0 kg/m2, P<0.05). NZEO and Pacific females of low food security were over twice as likely to be obese as the fully food secure (OR=2.16 & OR=2.61, respectively). Compared with Maori and Pacific males of fully/almost full food security Maori males of moderate food security (29.5 kg/m2 cf 31.3 kg/m2, P<0.05) and Pacific males of low food security (30.8 kg/m2 cf 33.3 kg/m2, P<0.05) had a higher BMI. Maori males of moderate food security compared to fully/almost fully secure males were over twice as likely to be obese (OR=2.15). There was no significant relationship between food security status and either BMI or likelihood of obesity for NZEO males. A decrease in dietary quality in females and males of both low and moderate food security was apparent compared to those of fully/almost full food security. Compared to males of fully/almost full food security and moderate food security status intakes of energy, glucose, fructose, vitamin C, lactose, calcium and zinc were all significantly lower among males of low food security. The proportion of daily energy from monounsaturated fat was significantly higher in males of moderate and low food security status than males of fully/almost full food security. The proportion of daily energy from total and saturated fat increased with lower household food security status, however this was not statistically significant. Females of low food security had lower intakes of vitamins A, C and folate compared with females in the other food security categories. Females of moderate and low food security status had lower intakes of glucose and fructose; and higher intakes of fat compared with the fully/almost fully food secure. These data are suggestive of poorer diet quality (higher in fat and lower in fruit and vegetables) in those of moderate and low food security compared with the fully/almost fully food secure females. Food security is a concern within New Zealand with a large proportion of the population experiencing food insecurity (moderate or low food security), with the problem of even greater severity for Pacific and Maori populations. The lack of full food security in New Zealand requires urgent action especially in light of its negative impact on both nutrient intake and body weight status. It is a serious public health problem.
Advisor: Venn, Bernard; Parnell, Winsome
Degree Name: Master of Science
Degree Discipline: Human Nutrition
Publisher: University of Otago
Keywords: Food security; New Zealand; Body weight
Research Type: Thesis