The aim of this paper is to examine the popularizing strategies adopted in the websites of the Matthew’s Friends Foundation (UK) and the Charlie Foundation (US), which promote information on the ketogenic diet (KD), a dietary treatment for intractable epilepsy. The study is part of a wider project meant to explore how knowledge is mediated to patients and their caregivers. The analysis uses discourse and corpus tools to explore the main differences between the two foundations in the use of knowledge dissemination strategies and in the construction of the relationship with the caregivers through the use of multiple textual voices (representing experts and the readers themselves). While focusing on similar aspects and using similar techniques, the two foundations differ in the frequency of use of explanations and question-answer sequences, as well as in the way they interpret their role as mediators of knowledge.