This study examined the contribution of metacognitive guidance to the development of drinking-related nutritional literacy(DNL). Metacognitive awareness promotes meaningful learning. Active involvement of students in metacognitive activities develops deep conceptual understanding. Childhood food and beverage consumption affects growth and can be a predictor of adult obesity, diabetes, and cardiovascular diseases. One of the factors that might improve food and beverage consumption is nutritional literacy. The research examined 225 students aged 9-11 and included a research and a control group. In both groups, students prepared and conducted an activity for students aged 6-8, as part of their science class. The activity sought to encourage the drinking of water and reducing the consumption of sweetened drinks. In the research group, the students received metacognitive guidance while preparing the activity. Changes in DNL in the areas of knowledge, attitudes, and behavior were tested by analysis of quantitative questionnaires. While there was no difference between the research and control groups in knowledge, the metacognitive guidance generated improvement in drinking-related attitudes and behavior. The improvement was seen both for everyday circumstances and at special occasions and emphasizes the great potential of expanding the relationship between metacognition and nutritional literacy.