PurposeThis study investigated the influence of marketing- and family-related factors on consumers' in-store usage of different types of food label information. Furthermore, the authors determined the mediating role of consumers' knowledge about healthy foods between these factors and their label consultation.Design/methodology/approachThe authors conducted a survey among 223 purposively selected South African working female consumers via social media. Subjective and objective knowledge about healthy foods, the importance of marketing- and family-related factors and the extent of food label usage were determined. Structural equation modelling served to test the mediating effect of knowledge in the relationship of the marketing and family-related factors with food label usage.FindingsMarketing-related factors demonstrated a strong direct effect on food label usage. Subjective knowledge about healthy foods mediated the relationship between family members' dietary needs and food label usage. However, objective knowledge was not a mediator.Practical implicationsRespondents' firm reliance on marketing-related factors (instead of knowledge) during food label usage is not in the best interest of consumers' healthy food choices. Healthy food choices based on factual knowledge rather than marketing efforts are necessary to establish long-term healthy food habits, hence the need for retailers' response in supplying healthier food options. Role players in consumer education should focus on increasing consumers' healthy food knowledge.Originality/valueIn the context of rising awareness of public health concerns, healthy food choice among consumers is essential. This study contributes to the complexity of consumers' need to make healthy food choices within an economic-driven marketing environment.