Background: Shared decision making (SDM) holds great potential for improving the therapeutic efficiency and quality of nutritional treatment of dyslipidaemia by promoting patient involvement in decision making. Adoption of specific behaviours fostering SDM during consultations has yet to be studied in routine dietetic practice.

Objective: Using a cross-sectional study design, we aimed to explore both dieticians’ and patients’ adoption of SDM behaviours in dietetic consultations regarding the nutritional treatment of dyslipidaemia.

Methods: Twenty-six dieticians working in local health clinics in the Quebec City metropolitan area were each asked to identify one dyslipidaemic patient they would see in an upcoming consultation. Based on the Theory of Planned Behaviour (TPB), questionnaires were designed to study two targeted SDM behaviours: ‘to discuss nutritional treatment options for dyslipidaemia’ and ‘to discuss patients’ values and preferences about nutritional treatment options for dyslipidaemia’. These questionnaires were administered to the dietician–patient dyad individually before the consultation. Associations between TPB constructs (attitude, subjective norm and perceived behavioural control) towards behavioural intentions were analysed using Spearman’s partial correlations.

Results: Thirteen unique patient-dietician dyads completed the study. Perceived behavioural control was the only TPB construct significantly associated with both dieticians’ and patients’ intentions to adopt the targeted SDM behaviours (P < 0.05).

Conclusions: As perceived behavioural control seems to determine dieticians’ and patients’ adoption of SDM behaviours, interventions addressing barriers and reinforcing enablers of these behaviours are indicated. This exploratory study highlights issues that could be addressed in future research endeavours to expand the knowledge base relating to SDM adoption in dietetic practice.