The aim of this paper is to analyze 1) the semantic content of tweets discussing diabetes and diets, and 2) the conversational connections of those tweeting and those being mentioned in the tweets. The content analysis of the tweets aims at mapping what kinds of diets are mentioned in conversations about diabetes and in what context. Our data consists of 9,042 tweets containing the words "diabetes" and "diet". The findings indicate that analyzing Twitter conversations can be an efficient way to map public opinions about diabetes and diets. The results also showed that many private persons act as diabetes advocates spreading information and news about diabetes and diets. Surveying these topics can be useful for healthcare practitioners; as these are in contact with patients with diabetes, it is important that they are aware of both the most discussed topics and the most common information sources, who are often laymen. © Springer International Publishing Switzerland 2014.