The adoption of carbohydrate-restrictive diets to improve health is increasing in popularity, but there is a dearth of research on individuals who choose to severely restrict or entirely exclude carbohydrates. The present study investigated the beliefs and experiences of individuals following a diet that severely limits, or entirely excludes, dietary carbohydrates, colloquially known as a ‘zero-carb’ diet, for at least 6 months. Zero-carb dieters (n = 170) recruited via a social networking site completed an online qualitative survey prompting them to discuss their motives, rationale, and experiences of following a low-carb diet. Transcripts of participants’ responses were analyzed using inductive thematic analysis. Results revealed that participants’ decision to follow a zero-carb diet was driven by health concerns and benefits. Participants expressed a strong social identity and belongingness to online zero-carb communities. Participants reported strong intentions to follow the diet indefinitely. Shortcomings of the diet centered on experienced stigma; lack of support from healthcare providers and significant others; limited access to, and high cost of, foods; and limited scientific data on the diet. Further research into the benefits and shortcomings of zero-carb diets across settings and populations is warranted, and guidelines for healthcare professionals on how to support individuals following a zero-carb diet are needed.