Information Paper
DIAMOND - FSANZ Dietary Exposure Assessment Computer Program
The DIAMOND computer program was custom built by Food Standards Australia New Zealand (FSANZ) to calculate dietary exposure to food chemicals such as food additives, pesticides, contaminants, nutrients and other food ingredients.
What is a dietary exposure assessment?
A dietary exposure assessment is the process of estimating how much of a food chemical a population, or population sub group, consumes. Dietary exposure to (or intake of) food chemicals is estimated by combining food consumption data with food chemical concentration data. This is called ‘dietary modelling’.
Dietary exposure = food chemical concentration x food consumption
What does DIAMOND stand for?
DIetAry Modelling Of Nutritional Data
How does DIAMOND know how to calculate dietary exposure?
DIAMOND is programmed using statistical software provided by software company SAS. A specialist SAS programmer is contracted by FSANZ to write the programming language that tells DIAMOND how to do the exposure assessment calculations. The programmer created a user friendly program for FSANZ that allows staff to tell DIAMOND what data to use and what calculations to use.
How is DIAMOND set up?
There are two main parts to the DIAMOND program: the data storage section and the exposure assessment section.
What data are stored in DIAMOND?
DIAMOND requires two main sets of data to estimate dietary exposure:
- the concentration of the food chemicals in specific foods
- data on the food consumption levels of those foods and the information about the consumers such as their age, gender and body weight.
There are other data sets also used including:
- food classification or grouping systems, so similar foods can be grouped together
- recipe datasets to break down mixed foods to their basic ingredients
- reference health standards which indicate a safe level of exposure or required level of intake.
Where do food chemical concentration data come from?
There are a range of sources of food chemical concentration data including:
- survey data for a wide range of chemicals, including data from total diet surveys and other government surveillance surveys
- trial data (for agricultural and veterinary chemicals)
- food composition tables (for nutrients)
- manufacturers' data for the level of use (for food additives and novel foods)
- maximum permission levels from food standards (Australia New Zealand Food Standards Code or other relevant international standards)
- maximum permitted level (MPL) for food additives
- maximum residue limits (MRL) for residues
- maximum levels (MLs) for contaminants
- permitted levels of nutrient fortification.
What foodconsumption data are used?
Food consumption data used in DIAMOND are from national nutrition surveys from both Australia and New Zealand. Those currently used are:
- 1995 Australian National Nutrition Survey (NNS) for 2 years and above
- 1997 New Zealand National Nutrition Survey (NNS) for 15 years and above
- 2002 New Zealand Children’s Nutrition Survey (CNS) for 5-14 year olds
- 2007 Australian Children’s Nutrition and Physical Activity Survey (CNS) for 2-16 year olds.
You can find out more information on the food consumption data FSANZ uses, including national nutrition survey (NNS) data, in another information sheet ( hyperlink here to food consumption info sheet )
What types of dietary exposure assessments can DIAMOND run?
Options exist within DIAMOND for running assessments or ‘models’ using different food consumption data and food chemical data. There isa:
- Chemical Intake Model that estimates dietary exposure to pesticides, contaminants, food additives and food ingredients
- Nutrient Intake Model that can estimate nutrient intakes for either a single day or over two days
- Food Intake Model that derives summary food consumption data only for specified foods or food groups.
Models can also be run for different age and gender groups, different ethnic groups, different socio-economic groups or groups with different dietary patterns.
How does DIAMOND use the data to estimate dietary exposure?
DIAMOND uses every person’s food consumption data from the national nutrition survey and works out what foods that they ate contain the food chemical being assessed. This includes finding out how much of each food they consumed from mixed foods. For example, how much milk they drank as a glass of milk as well as how much milk they consumed from sauces, puddings, cakes and other foods that contain milk.
Then DIAMOND multiplies the amount of food by the concentration of the chemical in that food. It repeats this for each food that contains the chemical.
For each person it adds up the estimated dietary exposure from all foods.
DIAMOND then divides the exposure by that person’s individual body weight (if required).
DIAMOND then ranks estimated dietary exposures for all people in the group being assessed and generates population statistics such as mean, median and 90th percentile exposure.
The exposures are then compared to the relevant reference health standards (if applicable).
We may report our results for ‘all respondents’, which means for everyone who took part in the national nutrition survey, or only for ‘consumers’, who are the subset of people who were exposed to the chemical in question, or for both respondents and consumers.
We may also subdivide respondents and consumers by age group or by gender, if this is relevant.
Average exposure or intake is reported as well as exposure or intake in the ‘high consumer’, representing those who have a high exposure to, or intake of, a particular food chemical ( HYPERLINK TO PROTECTING HIGH CONSUMER).
How long does it take to conduct an exposure assessment using DIAMOND?
DIAMOND can calculate an estimate of dietary exposure in a couple of minutes, but much more time is needed to obtain, format, check and enter the correct data into DIAMOND. After DIAMOND has calculated an estimate of dietary exposure, it again takes a longer period of time to extract, summarise and cross-check the required results and write a report on the methodologies, results obtained and conclusions of the exposure assessment.
How DIAMOND is used in dietary exposure assessments
The following diagram summarises the process of conducting a dietary exposure or intake assessment using DIAMOND:
A new DIAMOND
We have started the process of redeveloping DIAMOND and integrating it with another FSANZ data system, the Australian Nutrient Data Bank, to ensure that we can continue to produce high quality dietary exposure assessments and food composition publications. It will also incorporate enhanced data storage capabilities. We anticipate this redevelopment process will be completed in mid-2011.
For more information:
See the fact sheet “ Dietary exposure and intake assessments at FSANZ ” , or the document “FSANZ Dietary Exposure Assessment Principles and Procedures ”.
Or email the FSANZ Dietary Modelling Team at http://www.foodstandards.gov.au/contactus/contactform.cfm