Objective understanding of front of pack warning labels among Mexican children of public elementary schools. A randomized experiment

Self-reported decreases in the purchases of selected unhealthy foods resulting from the implementation of warning labels in Mexican youth and adult population

Background

Front-of-package nutritional warning labels (WLs) are designed to facilitate identification and selection of healthier food choices. We assessed self-reported changes in purchasing different types of unhealthy foods due to WLs in Mexico and the association between the self-reported reductions in purchases of sugary beverages and intake of water and sugar-sweetened beverages.

Methods

Data came from 14-17 year old youth (n=1,696) and adults ≥18 (n=7,775) who participated in the Mexican arm of the 2020-2021 International Food Policy Study, an annual repeat cross-sectional online survey. Participants self-reported whether the WLs had influenced them to purchase less of each of ten unhealthy food categories due to WLs. Among adults, a 23-item Beverage Frequency Questionnaire was used derive past 7-day intake of water and sugary beverages analyzed to determine the relationship between self-reported reductions in purchasing sugary drinks due to the WLs. Multilevel mixed-effects logistic regression models were fitted to estimate the percentage of participants who self-reported reducing purchases within each food group, and overall. Sociodemographic characteristics associated with this reduction were investigated as well.

Results

Overall, 44.8% of adults and 38.7% of youth reported buying less of unhealthy food categories due to the implementation of WL, with the largest proportion reporting decreased purchases of cola, regular and diet soda. A greater impact of WLs on the reported purchase of unhealthy foods was observed among the following socio-demographic characteristics: females, individuals who self-identified as indigenous, those who were overweight, individuals with lower educational levels, those with higher nutrition knowledge, households with children, and those with a significant role in household food purchases. In addition, adults who reported higher water intake and lower consumption of sugary beverages were more likely to report reduced purchases of sugary drinks due to the WLs. Adults who reported greater water intake and lower sugary beverages intake were significantly more likely to report buying fewer sugary drinks due to the WLs.

Conclusion

Our findings suggest that implementation of WLs has reduced purchases of unhealthy foods in Mexico. These results underscore the positive impact of the labeling policy particularly in subpopulations with lower levels of education and among indigenous adults.

Efficacy of front-of-pack warning label system versus guideline for daily amount on healthfulness perception, purchase intention and objective understanding of nutrient content of food products in Guatemala: a cross-over cluster randomized controlled experiment

BACKGROUND

Front-of-package warning labels (FOPWL) have been adopted in many countries aiming at reducing the consumption of unhealthy food and drink products and have also been considered in Guatemala. The aim of the study is to evaluate the efficacy of FOPWL versus Guidelines for Daily Amount (GDA) on products' healthfulness perception (HP), purchase intention (PI) and the objective understanding of the nutrient content (UNC) in Guatemala.

METHODS

Participants (children and adults) (n = 356) were randomly assigned to evaluate either FOPWL or GDA during a crossover cluster randomized experiment in rural and urban areas across 3 phases of exposure. During phase 1, participants evaluated mock-up images of single products (single task) and compared pairs of products within the same food category (comparison task) without any label. In phase 2, participants evaluated labels only (without any product), and during phase 3, they evaluated the same products and questions from phase 1, now depicting the assigned front-of-package label. We generated indicators for single-task questions and scores for comparison tasks, one for each HP, PI and UNC questions. We used intention-to-treat, difference-in-difference regression analysis to test whether exposure to FOPWL was associated with HP, PI and UNC, compared to GDA. We also tested models for children and adults and by area (rural/urban) separately adjusting for sociodemographic variables.

RESULTS

In single tasks, FOPWL significantly decreased the PI (β -18.1, 95%CI -23.3, -12.8; p < 0.001) and the HP (β -13.2, 95%CI -18.4, -7.9; p < 0.001) of unhealthy food products compared to GDA. In the comparison task, FOPWL significantly increased the UNC (β 20.4, 95%CI 17.0, 23.9; p < 0.001), improved PI towards healthier choices (OR 4.5, 95%CI 2.9, 7.0 p < 0.001) and HP (OR 5.6, 95%CI 2.8, 11.1; p < 0.001) compared to GDA. Similar results were found in children and adults and in urban and rural settings.

CONCLUSIONS

FOPWL reduces products' healthfulness perception and purchase intention, and increases understanding of products' nutrient content compared to GDA.

Uncovering the Effect of European Policy-Making Initiatives in Addressing Nutrition-Related Issues: A Systematic Literature Review and Bibliometric Analysis on Front-of-Pack Labels

The last decades have been marked by the introduction of front-of-pack labels (FoPL) as an institutional corrective action against obesity and nutrition-related illnesses. However, FoPL-related policy-making initiatives issued by the European Union evolved over time and led to a diversity of labels with different effects on consumers’ decisions. As a result, the extant literature adapted to the regulative scenario over the years and investigated the effects of the labels, creating consensus on some topics while being fragmented on others. Similarly, policy-makers adapted some regulations to the evidence supported by the research. With the aim to systematize the overall structure and evolution of the literature on FoPL, investigate the presence of a consensus on specific topics through a co-citation analysis, and examine the evolution of the consensus and co-citation networks over the years and potential research gaps, we report the results of bibliometric and co-citation analyses and a systematic literature review involving 170 papers and a selection of 49 articles published in the last months, for a total of 219 articles, analysed according to three timespans (Period 1 (1989–2011); Period 2 (2012–2016) and Period 3 (2017–2022)). Our findings highlight the interplay of policy development and FoPL research, the presence of few self-reinforcing and well-established co-citation networks based on validated evidence in the literature and the presence of alternative emerging theories that offer different and valid perspectives overlooked by mainstream co-citation research networks.