This study focuses on an educational proposal on nutrition within the framework of a context-based approach to science teaching. The intervention was conducted with 100 students between the ages of 9 and 15 in the City of Buenos Aires with the intention of developing their ability to identify checkable and non-checkable claims. Even when it has been noted that a short training can improve this ability in adults, for the first time we have evidence that shows an educational intervention is also likely to improve it in elementary and high school students. This improvement seems to persist over time, compared to the control group. A first approach to the possibility of transferring these abilities to other areas that are not related to nutrition has also shown positive results.