Added Sugar in Processed Foods and Beverages in New Zealand and the Role of Free and Added Sugars on Health

Abstract

Background: Increases in sugar consumption, particularly from free and added sugars, has been linked to several nutrition-related risk factors and diseases including obesity, cardiovascular diseases and related risk factors, dental caries and diabetes (types 1 and 2) (1). Free sugars are defined by the World Health Organization (WHO) as monosaccharides and disaccharides added to foodstuffs by the consumer, manufacturer or cook, and sugars that are present in syrups, honey, fruit juice and fruit juice concentrates (1). Although there is no agreed definition of added sugars universally, added sugars refer to the same group of sugars as free sugars and are defined by the United States Department of Agriculture (USDA) as refined sugars added during manufacturing or cooking. (2). Recently the WHO published guidelines on sugar intake, recommending that the intake of energy from free sugars should be < 10%, or < 5% for additional health benefits (1). In recent years, added sugar consumption has become a matter of interest, with special attention focused on its health effects and nutritional properties (3). However, there are limitations regarding the calculation of added sugar in foods and diets as it is difficult to distinguish chemically from total sugar. Therefore, there is a need for a simple, robust and reliable analytical method to estimate accurately the quantity of added sugar in packaged foodstuffs. Added sugar is a relatively new concept, and due to the lack of simple methods for calculation, there is limited evidence concerning the quantity of added sugars and their association with health outcomes. Objective: The objective of this thesis is three-fold: (1) To undertake a systematic literature review to identify existing, simple, robust and reliable methods for calculating added sugars in processed foods and beverages; (2) to undertake a systematic review of published literature to explore the association of free and added sugars intake with health outcomes; and (3) use the method identified in (1) to calculate the added sugars content of key food groups in an existing packaged food composition database (Nutritrack 2015) to identify which foods and beverages should be the focus of reformulation and reduced serving sizes. Design: For objectives (1) and (2), a systematic review was undertaken across articles published in English in the following databases: Cochrane Library, Embase, Google Scholar, Medline, Scopus and Food Science and Technology Abstract (FSTA). For objective (3) the Louie et al. (4), methodology identified in (1) was adapted and applied to five packaged food categories of New Zealand (NZ) known to contain high levels of total sugars: cereal and cereal products, dairy, fruit and vegetables, non-alcoholic beverages and sauces and spreads. Results: Two published studies estimating free and added sugar values were included in the first review: (1) Louie et al. (4) outlined a 10-step systematic methodology to calculate added sugars in food products based on food composition data, and (2) Sluik et al. (5) estimated total, free and added sugars using product information and labelling from Dutch food composition tables. Sixteen studies were included in the second review (two randomised control trials (RCTs) and fourteen observational studies). There were inconsistent findings on the association between dietary sugars intake and body mass index (BMI), blood pressure, high density lipoprotein (HDL) and low density lipoprotein (LDL) cholesterol. However, positive associations were reported between dietary sugars intake and weight gain, increased waist circumference, cardio-metabolic risk factors, types 1 and 2 diabetes, endometrial cancer and dental caries. For objective (3), 4,882 (88%) of foods had added sugars calculated objectively (steps 1-5) and 667 (12%) using subjective steps (step 7). For the five food groups assessed, rankings for the quantity of added sugars by food group differed depending on whether the ranking was done per 100 grams (g) or per serve. Per 100g the food group with the highest mean standard deviation (SD) was cereal and cereal products (11 (14) g/100g) followed by dairy (5 (11) g/100g). Per serve the food group with the highest amount of added sugar was cereal and cereal products (26 (56) g/serve) followed by sauces and spreads (7 (23) g/serve) The best food categories to reformulate for public health gains per 100g and per serve were puff-based bars, ice cream, desserts, cordials, energy drinks, soft drinks and spreads. Furthermore, reducing serving size especially for products with a single serve such as yoghurt and yoghurt drinks and cereal bars would reduce added sugar intake. Conclusion: The current systematic methodology developed by Louie et al. (4) is currently the simplest, most robust and reliable approach to calculating the added sugars content of packaged foods. There are inconsistent findings in observational and randomised control trials on the association between dietary sugars intake and BMI, blood pressure, HDL and LDL cholesterol. Positive associations were reported between dietary sugars intake and cardio-metabolic risk factors, types 1 and 2 diabetes, endometrial cancer and dental caries. Therefore, food categories that should be the focus of public health interventions include: cereal bars, meat accompaniment sauces, puff-based bars, ice cream, desserts, cordials, energy drinks, soft drinks and spreads.