Background Poor nutrition has been associated with lack of nutrition education, which leads to chronic diseases like diabetes, hypertension, obesity and coronary artery diseases. The objectives of the study were to evaluate learners’ knowledge of nutrition education principles and to determine how the knowledge of nutrition principles could be improved among learners. Methods Mixed methods cross-sectional research with application of semi-structured face-to-face interviews and a structured questionnaire were used to collect data. Eight stake-holders participated in the qualitative component of the study while 108 learners from 8 different schools responded to the questionnaire. The qualitative data was analyzed by coding and categorizing the data into themes and sub-themes while the quantitative data was analyzed using SPSS yielding frequencies, percentages, means and standard deviations. Results A significant proportion of learners lacked the nutrition knowledge due to the absence of health promotion campaigns in the schools and teaching of the nutrition principles was only limited to Life Science in the high school curriculum. Majority (56%) of the learners were taught nutrition education at primary school mainly in the Life Orientation curriculum while less than 2% were taught in grade 11 and 12. About 92% of the learners were not aware of the nutritional value of fruits, vegetables, milk and fats. Conclusions Incorporation of nutrition education in a compulsory subject in high school and in-school nutrition education sessions in school gatherings that involve various stakeholders is critical in improving the nutrition knowledge of stakeholders. Such interventions will assist in curbing diet related chronic diseases.