The distribution of school-aged adolescents’ free sugar intake across the day: A cross-sectional study

Objective: We aimed to explore how free sugar intake varies across the day in secondary school pupils. 

Methods: Pupils aged 11-15 years were recruited between December 2019-April 2022 from English secondary schools. Pupils completed a sociodemographic questionnaire and recorded all foods and drinks consumed in the previous day. We undertook mixed-effects regression modelling to explore patterns of sugar consumption across different eating occasions, and in and out of school, accounting for school clustering and adjusting for energy intake and participant sociodemographic variables. 2575 pupils were invited to participate, with 2273 participants ultimately included in the study. 

Results: After adjustment for mealtime energy intake, compared to breakfast, free sugar intake was lower at lunch (mean difference: -7.86 g; 95% CI = -8.87 g, -6.84 g; p = <0.001) and dinner (mean difference: -11.82 g; 95% CI -12.85 g, -10.80 g; p = <0.001). Free sugar intake from snacks was higher than breakfast (mean difference: 7.70 g; 95% CI 6.68 g, 8.72 g; p = <0.001). Snacks on average comprised 28.5% of total energy intake and 43.1% of free sugar intake for the day. Free sugar intake outside of school was higher than intake during school time (mean difference: 3.18 g; 95% CI = 1.67 g, 4.69 g; p = <0.001). 

Conclusion: Breakfast and snacks made the largest contribution to free sugar intake among adolescents in the study after accounting for variation in energy intake across mealtimes. Free sugar intake was higher outside than inside school. Efforts to reduce free sugar intake in adolescents should focus on breakfast and snack food and drink items, and high sugar items available outside of school.