How much added sugar is in that? A proposed method for calculating added sugars in foods
Because natural and added sugars are chemically identical, analytical testing is not feasible to determine the added sugar content in foods. Because added sugar data are not available, dietary surveys have not quantified added sugars consumption. Local researchers from Sydney University have proposed their own methodology for estimating added sugars in foods and now have two papers published.
How does the method work?
Their first paper outlines the methodology. Jimmy Louie and colleagues propose a 10 step protocol based on using compositional data and ingredients in food products: objective data in the first 6 steps; and an additional 4 subjective steps if objective data are not available.
10 Step Protocol for Estimating added sugars in foods
Step 1: Assign 0 g added sugar to foods with 0 g total sugars.
Step 2: Assign 0 g added sugar to foods that are minimally processed and typically don't have added sugar (eg fats and oils, eggs, meat, fresh fruits and vegetables, nuts, legumes, grain foods, herbs and spices, 100% fruit juices)
Step 3: Assign 100% of total sugars as added sugar for foods that typically contain minimal amounts of natural sugars (eg regular soft drinks, sugar and syrups, non-dairy based confectionary, breakfast cereals and bars without dairy or fruit ingredients, processed meats, battered/crumbed meats, biscuit and bakery items without dairy or fruit ingredients, soy beverages and yoghurt without dairy or fruit ingredients and stock powders).
Step 4: Calculation based on standard recipe used in the food composition database—proportioning method where added sugar content of ALL ingredients were available from steps 1 to 3.
Step 5: Calculation based on comparison with values from the unsweetened variety.
Step 6: Decision based on analytical data, such as lactose and maltose content if available.
Step 7: Use borrowed values from similar products from steps 1 to 6, or overseas food composition databases.
Step 8: Subjective estimation on the basis of ingredients and/or common recipes (e.g., obtained from popular recipe books).
Step 9: Calculation based on the standard recipe that includes ingredients with values assigned at steps 5–8, using the proportioning method
Step 10: Assign 50% of total sugars as added sugar.
They applied the method to the AUSNUT2007 food composition database. They estimated all sugars added during manufacturing or cooking, including sucrose, monosaccharides and disaccharides (e.g., fructose, lactose), syrups (eg corn, malt, maple, sorghum), maltodextrin and fruit juice concentrates.
What did they find?
Out of the 3874 foods available in AUSNUT2007, 2977 foods (77%) were assigned an estimated value on the basis of objective measures (steps 1–6), and 897 (23%) were assigned a subjectively estimated value (steps 7–10). Some examples of the foods subjected to this protocol are listed below.
|Food||Added sugar (g)||Total sugar (g)|
|Chocolate milk, regular fat||3.9||8.2|
|Vanilla yoghurt (4.5% fat)||8.4||12.0|
|Tomato sauce, commercial||20.7||23.3|
|Cinnamon sugar doughnut||13.7||13.7|
|Iced banana cake, homemade||31.5||34.8|
What are the advantages?
This method is an improvement on previously devised methods, most notably the USDA added sugar database that has been withdrawn due to the difficulty in maintaining currency. This protocol relies less on 'blanket estimation' of added sugar content within food categories than other methods (such as the International Choices Programme criteria for front-of-pack labelling in Europe) and this better reflects the variation of added sugar content in the Australian and New Zealand (ANZ) food supply.
There were no significant differences between added sugar estimates between two researchers demonstrating a good inter-researcher repeatability.
What are the limitations?
Food composition databases struggle to keep up with the constantly changing food supply and this method relies on food composition data- maintaining currency is a challenge. Databases are also not comprehensive; in this case the AUSNUT database only contains 3874 foods, whereas a typical Australian supermarket contains around 80,000 products. Assumptions are made about whether food categories contain added sugars or not, and there are always exceptions. This method relies on the lactose content of foods being known, and all lactose present being natural, and this is not always the case. It also relies on ingredients being listed on food labels in order by weight, and ideally percentage labelling of major ingredients as is the case in ANZ, and this may impair its validity in other countries without these requirements. The method assumes standardised recipes when in fact there is considerable variation. The protocol is reliant on people (in this case dietitians and nutrition scientists) with reasonable food and nutrition knowledge and limits the large scale uptake of the method.
This method is comparatively simple and has good repeatability to estimate the added sugar content of foods. The accuracy of the method is unknown. Despite its limitations, it's the only method currently available for estimating added sugars in Australian foods.
Louie JC, Moshtaghian H, Boylan S, Flood VM, Rangan AM, Barclay AW, Brand-Miller JC, Gill TP. A systematic methodology to estimate added sugar content of foods. Eur J Clin Nutr. 2015 Feb;69(2):154-61.
How much added sugar are Australians eating?
The second paper used this method to estimate the added sugars in the dietary intake data collected in the 2011-12 Australian Health Survey. And in order to benchmark Australian population against the WHO limit of 10% energy from free sugars (10%EFS), free sugars were also analysed by tweaking the protocol to suit the wider WHO definition of free sugars. Food and beverage intakes were then converted into energy and nutrient intakes using the AUSNUT 2011-13 food composition database.
Added sugars vs free sugars: what's the difference?
Added sugars are defined as sugars and syrups added to foods and beverages as they are processed or prepared (the USDA definition), whereas free sugars are defined by WHO as 100% of added sugar for non-fruit juice sources (including honey and syrups) and 100% of total sugars for fruit juices and drinks. The WHO definition is broader.
What did they find? How much added sugars are we eating?
The mean daily added and free sugar intakes of the study population (8202 people aged 2 years and over) were 60 g and 65 g, contributing 11 and 12% of total energy intake, respectively. The percentage energy from added sugar is similar to analysis of the 1995 National Nutrition Survey (NNS) by Cobiac et al . Adults aged 19 years and over consumed an average of 58g added sugars daily (10%E) but with large standard deviations reflecting a wide variety of intakes. Adolescents 14-18 are the highest consumers of added sugars (88g/day; 13.6%E) in both analyses, with most coming from sugar sweetened beverages. Compared with the 2007 Australian National Children's Nutrition and Physical Activity Survey, more children and adolescents are now meeting the WHO 10%EFS guidelines (27.3% vs 14.7%). Using the WHO free sugars definition, 55.7% of the population are consuming more than 10% energy as free sugars.
Where did the added sugars come from?
|Food category||% contribution of added sugars|
|Sugar sweetened beverages||21.4% (SD 30)|
|Sugar and sweet spreads||16.3% (SD 24.5)|
|Cakes, biscuits, pastries and batter based products||15.7% (SD 24.4)|
Sugar sweetened beverages, sugar, sweet spreads, cakes, biscuits, pastries and batter based products accounted for more than 50% of added sugar intake. The majority (80-90%) of daily added sugar came from nutrient-poor discretionary foods. Core foods such as breakfast cereals and dairy foods contributed only 15% of added sugars
What are the limitations?
Whilst we now have a method to estimate added sugars in the diet, the 10 step protocol outlined above has not been validated, although, the authors say it has been peer reviewed and deemed to have good face validity. Unfortunately the 24 hour recall method is not an accepted method for use with children as parental recall is not accurate. There are shortfalls in using 24 hour recalls as they may not be representative of usual intake. The population data showed large standard deviations indicating a wide variety of added sugar intakes.
The authors concluded that efforts to reduce added sugar intake should focus on reducing consumption of discretionary foods and drinks and promotion of water and healthy core foods. We would add: adolescents are the greatest consumers of sugar sweetened beverages and a prime target group for intervention; and, due to the wide variety of added sugar intakes more targeted interventions toward higher consumers of added sugars would likely be more effective than broader population approaches.