Self-regulation of eating behaviour refers to the ability to make healthy dietary choices, resist temptation and maintain a healthier diet over the longer term through monitoring, controlling and modifying thoughts, feeling and behaviour in response to food and related cues. Greater nutrition knowledge appears to be correlated with improved self-regulatory capacity, but evidence is lacking. The present study explored self-regulation capacity of individuals with knowledge of nutrition versus a lay audience. A total of 71 participants completed an online survey measuring nutritional knowledge, general self-regulatory capacity, the self-regulation of eating, trait eating behaviours and body image perception. General self-regulation capacity was negatively correlated with nutrition knowledge scores (r = −.320, p = .017), where greater self-regulation was associated with poorer nutrition-related knowledge. There was no correlation between self-regulation specific to eating behaviour and nutrition knowledge (r = −.064, p = .634). These findings suggest a poor link between self-regulatory capacity and nutrition knowledge. However, findings show a link between self-regulation, perceived struggle to maintain a healthy weight and disordered eating behaviours (e.g., uncontrolled and emotional eating), suggesting dietary self-regulation may be important for preventing problematic eating behaviours.