Primary school children exhibit socioeconomic inequalities in their usual beverage consumption: baseline assessment of the DRINK trial

Promoting favourable beverages to children remains a public health priority, and schools are essential in reducing nutritional disparities. The study aimed to describe the baseline characteristics of schools and children included in the DRINK trial, and to examine disparities in children’s usual beverage consumption.

The study is a cross-sectional analysis of data collected at baseline of the DRINK cluster randomised controlled trial. Children aged 8–11 years from 46 French-speaking primary schools in Belgium were invited to complete 4-day diaries and questionnaires during the spring 2021. Usual consumption of total beverages, water, sweetened beverages (SB), and milk was estimated by correcting the data for within-person variation using the Statistical Program to Assess Dietary Exposure (SPADE) and compared between subgroups using bootstrapping to generate 95% CIs.

A diverse range of schools and children participated in the trial. Of the 3,631 students, 2,427 completed a valid diary and child questionnaire, including fewer from Brussels than Wallonia. Children usually consumed 1,109 ml/day (95% CI: 1,092–1,132) of total beverages, including 677 ml/day (660–699) of water, and 345 ml/day (331–359) of SB. Socio-economic disparities were observed in all types of beverage consumption, mostly related to the parental education, and most strikingly for the water intake.

Despite the challenges of participation, partly due to the Covid-19 pandemic, inclusion in the DRINK trial provided a wide diversity of school populations, which will ultimately be considered when interpreting the trial findings. The overall high consumption of SB and the socio-economic disparities, particularly in water consumption, emphasize the need to reinforce nutrition interventions among disadvantaged children.

The DRINK trial was registered on 25 May 2021 in the ISRCTN Registry (ISRCTN99843102).