Identification and understanding of precautionary legends used in the Mexican front-of-pack warning labeling system for sugar-sweetened beveragesObjective: To evaluate the identification and objective understanding of precautionary legends regarding non-sugar sweeteners (NSS) and caffeine in sugar-sweetened beverages (SSBs). Materials and methods: The labeling questionnaire from the National Health and Nutrition Survey 2021 was given to 8,811 Mexican adults. Identification was evaluated when the participants reported seeing the legend. Objective understanding was considered as correctly evaluating the nutritional quality of SSBs. For this evaluation, 50% of the participants were presented with an image of a sugary drink with the precautionary legend and the other 50% without the legend. Results: For the NSS legend, the odds of correctly evaluating the nutritional quality of a SSB were higher for participants who identified the NSS legend (OR: 1.62, 95% CI 1.12, 2.34) compared to those who did not. Odds were also higher when the product was presented with the legend compared to when it was not (OR: 1.23, 95% CI 1.01,1.51). For the caffeine legend, the odds of correctly evaluating the nutritional quality of a SSB were three times higher among people who identified the legend compared to those who did not (OR: 3.21, CI 95% 1.63, 6.3). Discussion: Better performance was observed among participants who identified the legends. We recommend implementing strategies to enhance the identification of precautionary legends.