Objective:To explore adherence to a plant-based diet from the perspective of goals- and motivations-based systems.Design:A cross-sectional, survey-based study was conducted regarding eating patterns, goals and motivations for current eating habits.Setting:Data were collected using an online survey platform, including the Goal Systems Assessment Battery (GSAB) and other survey tools.Participants:University students were recruited, including thirty-three students reporting successful maintenance of a plant-based diet (Adherents) and sixty-three students trying to adhere to a plant-based diet (Non-adherents).Results:Using GSAB subscale scores, discriminant function analyses significantly differentiated adherentsv. non-adherents, accounting for 49·0 % of between-group variance (χ2(13) = 42·03,P< 0·000). It correctly classified 72·7 % of adherents and 88·9 % of non-adherents. Constructs including value, self-efficacy, planning/stimulus control and positive affect were significant and included in the discriminant function. Logistic regression results suggested that participants who successfully adhered to a plant-based diet were seventeen times more likely to report ‘To manage or treat a medical condition’ as motivation and almost seven times more likely to report ‘To align with my ethical beliefs’ as motivation compared with non-adherents. However, these participants were 94 % less likely to report ‘To maintain and/or improve my health’ as motivation compared with non-adherents. Controlling for motivations, hierarchical logistic regression showed that only planning as part of the GSAB self-regulatory system predicted adherence to a plant-based diet.Conclusions:Values-based approaches to plant-based diets, including consideration for ethical beliefs, self-efficacy and proper planning, may be key for successful maintenance of this diet long-term.