In Spain, 40% of children are overweight or obese. Television advertising is a widely acknowledged factor contributing to high-calorie food intake. This study longitudinally correlates some variables involved in childhood obesity prevention strategies in Spain. A mixed-methods approach was used. A quantitative analysis of audience data was conducted to determine the advertising campaigns most viewed by Spanish children from 2016 to 2018. The Nutri-score system was applied to determine the nutritional quality of the food advertised. A content analysis and a study of the discursive strategies used as an advertising ploy was undertaken. The results were examined in relation to the regulatory framework of the Spanish PAOS Code for the co-regulation of food advertising aimed at children. The study shows that Spanish advertising aimed at children mostly advertises very low nutritional value products. Moreover, these campaigns violate the PAOS Code in terms of the use of language in relation to the product, its benefits, and the appearance of popular characters. Our findings suggest a direct association between low nutritional value food ads and discursive strategies based on the intangible and extrinsic characteristics of these products. There remains the need for stricter legislation that takes into consideration the nutritional value of advertised foods and the language used in their hedonistic advertising.