The nutrient data in AUSNUT 2011-13 has undergone an extensive data validation process, with portions of the database also undergoing an external peer review process.
Internal validation of nutrient data
FSANZ undertook a series of internal data validation activities. Some validation activities focused on individual foods and beverages, while other activities focussed on specific nutrients, food categories, recipes, factors and system calculations.
Some of the routine validation activities undertaken by FSANZ include checking:
- all foods have a value for all nutrients to be reported
- the sum of proximates for each food and beverage falls between 95 and 103 g/100 g unless the food is known to have a low sum of proximates (e.g. coffee powder, high salt foods, some high fibre foods)
- no single nutrient value is greater than 101 g/100 g
- the sum of individual fatty acids (gram basis) is slightly less than the total fat value
- the sum of fatty acids (% basis) is between 97 and 103%
- fortified foods contain higher levels of the fortificant then the unfortified equivalent
- low fat or low sodium foods contain lower fat and sodium values then the regular equivalent
- plant foods have zero cholesterol, retinol and vitamin B12 unless fortified
- there are no unexpected sources of caffeine and alcohol
- the appropriate nitrogen factor and fat factor have been applied to non-recipe foods
- recipes use correct ingredient proportions, weight change factors and retention factors
- the equations are being applied correctly and the system is performing all recipe and non-recipe calculations as expected
- nutrient values are consistent with the known composition and with related foods, where appropriate.
FSANZ also undertook some more targeted validation activities including:
- focussing more detailed checks on the most frequently consumed foods and foods that were likely to be the main drivers of intake of specific nutrients
- commissioning a series of analytical programs to verify recipe and imputation assumptions (2012 Cake and slice program, 2013 Unfortified breakfast cereal program, 2013 Specialty bread program), or to confirm values of specific nutrients in some foods (2013 potato program)
- purchasing a range of takeaway foods (including hamburgers, sushi, wraps) and determining the gross composition of the product to validate the ingredient proportions used in recipe calculations (e.g. the proportion of bread roll, meat, cheese, egg, bacon and salad in a takeaway 'burger with the lot').
External peer review of nutrient data
FSANZ provided parts of the AUSNUT 2011-13 food nutrient database to a range of food composition experts and the relevant sector of the food industry for review. The review mainly focussed on nutrients that had not been reported in previous National Nutrition Surveys such as vitamins B6 and B12 and selenium, and some specific food categories (including grains and legumes, snack foods (potato crisps, nuts and chocolate), dairy products, meat and poultry, margarine spreads etc).