The Impact of Front-of-Pack Labeling on Social Inequality in Sugar Consumption and Purchase: A Systematic Review.

Abstract

This systematic review examined the impact of front-of-pack labeling (FOPL) on social inequality in sugar consumption and purchase. We searched Ovid MEDLINE, Scopus, EMBASE, and Web of Science for studies published in English since 2005. Eligible studies included randomized controlled trials and observational studies. The screening was conducted independently by at least two reviewers. Data extraction and quality assessments were cross-checked. The risk of bias was assessed using ROBINS-E, RoB2, and CHEERS 2022. A narrative synthesis summarized the findings. Of the total of 7701 studies identified, 10 studies were included. All included studies were conducted in high- and upper-middle-income countries, and primarily evaluated one specific type of FOPL, specifically warning labels (n = 8). All studies reported FOPL reduced sugar consumption at the population level. However, findings on social inequality were inconsistent. Five studies showed greater benefit among higher-socioeconomic groups, four among lower-socioeconomic groups, two identified a U-shaped effect, and two found no differential effect by socioeconomic status. The overall quality of studies was poor. FOPL, in particular warning labels, can reduce sugar consumption, but its effects on socioeconomic inequalities were inconsistent. Evaluation of high-quality longitudinal research is needed to ensure FOPL interventions are inclusive and effective across socioeconomic groups.