Development of a food security measurement tool for New Zealand households

To determine the prevalence of household food insecurity in New Zealand (NZ), eight food security statements were included in the 1997 National Nutrition Survey of adults. Rasch model analysis was performed to determine whether each food security statement (addressing a food security attribute) was discrete and could be ranked on a unidimensional scale. The NZ model had marginal 'household' reliability (0·60-0·66), good item separation (17·20-17·77) and item infit/outfit values between 0·8 and 1·25. Indices could be ranked by level of severity and represent the experience of household food insecurity in NZ. Categories of food security were assigned and used to predict food choice, and energy and nutrient intakes. Compared with fully secure/almost fully secure households, those that were moderately secure or of low security were less likely to consume the recommended daily servings of fruit and vegetables, and more likely to consume fatty meats. Intake of total fat, saturated, monounsaturated and polyunsaturated fat, cholesterol, lactose and vitamin B12 increased with lower levels of food security. Intakes of glucose, fructose and vitamin C were highest in the fully secure/almost fully secure category. This unique eight-component food security measurement tool has less respondent burden than the US Core Food Security Measure. The relationships between the level of food insecurity and food choice and nutrient intakes illustrate that the most food-insecure households have less healthy diets. This relatively brief population-specific measurement tool is suitable to monitor population food security status, and is a useful marker of nutritional status.