Added sugar intakes and food sources in New Zealand adolescent boys aged 15-18 years

Abstract

Background: High added sugar intake is often associated with increased body weight and oral health problems. Despite media attention over the past few years, added sugar intake in adolescents was last assessed using the data from the New Zealand Adult Nutrition Survey (NZ ANS) 08/09.

Objectives: The aim of this cross-sectional study was to investigate added sugar intake and food sources in adolescent boys enrolled in New Zealand (NZ) secondary schools. The data in this thesis formed part of a nationwide study, the Survey of Nutrition Dietary Assessment and Lifestyle (SuNDiAL) project.

Design: Adolescent boys aged between 15 and 18-year-old enrolled in schools across NZ were recruited via in-school presentations. Once the participants consented, they were required to perform an online questionnaire asking their sociodemographic, health and dietary habits. Anthropometric measurements (height, weight, ulna length) and blood pressure were measured at schools. Dietary information was taken by performing two 24-hour dietary recalls (first was done in-person, second was done via phone/video call). Dietary data were entered into FoodWorks 9 (Xyris Software Australia Pty Ltd). Multiple Source Method (MSM) was used to adjust for usual intake. Intakes of total sugar and individual sugars (glucose, fructose, lactose, sucrose) were reported. As added sugar variable was unavailable in the Foodfiles 2018 database, the amount of sucrose reported in this study was interpreted directly to be assumed added sugar. Natural sugar was calculated by deducting the amount of assumed added sugar from total sugar.

Results: The ethnicities distribution in this study was made up of 54.1% NZ European, 8.9% Maori, 2.2% Pacific and 30.4% Asian. Approximately 32% of the boys were classified as overweight or obese. The mean (95% CI) intake of total and assumed added sugar were 100 (92, 108) g/d and 44 (39.7, 48.3) g/d respectively. The top five contributing food sources of assumed added sugar were fruit; non-alcoholic beverages; sugar/sweets; cakes and muffins; biscuits. Most of the boys (99%) met the recommendation by the United States Department of Agriculture (USDA) of <10% of total energy intake from added sugar. When assumed added sugar was used in-place of free sugar, only about 4% of them met the conditional recommendation by the World Health Organization (WHO) of <5% of total energy intake from free sugar.

Conclusion: Compared with the last nationally representative nutrition survey, there appears to be a reduction in total and added sugar (sucrose) consumption. The results should be cautiously interpreted given the limitations in measuring added sugar intake. There is also a shift of food sources of added sugar where intake of non-alcoholic beverages has reduced. However, education on food sources of added sugar should still be focused on future nutritional interventions. This inclusion of added sugar as a variable in New Zealand FoodFiles would also provide a more robust estimate of added sugar intakes in this demographic. Therefore, our data collected from a convenience, non-representative sample are suggestive, rather than being definitive, of added sugar intakes in adolescent boys. This uncertainty in intake warrants further research at a nationally representative level. A survey of adolescent attitudes to added sugar could help clarify shifts in consumer purchasing.