This study was conducted to increase knowledge on the associations of psychosocial factors with the maintenance of a healthy lifestyle among breast cancer survivors. The main results show moderate levels of physical activity and healthy diet maintenance. Whereas healthy diet maintenance was associated only with lower perceived discrepancy, higher physical activity was also associated with higher self-compassion, lower use of expressive suppression, and higher use of cognitive reappraisal. Moreover, self-compassion was associated with physical activity via the mediation of cognitive reappraisal and expressive suppression.

Although the average level of activity in the present study was moderate, the reported levels of activity varied widely, with about 70% of participants under the suggested activity level, in line with previous reports [28]. Although previous studies used various measures of activity, similar rates of insufficient activity were reported [10, 42]. For example, in Busen and colleagues’ study [42], nearly 60% of the participants did not meet recreational physical activity guidelines. In another study, 41.6% of survivors reported not partaking in any exercise or engaging in low levels of physical activity [10]. Similarly, 41% of participants in the current study indicated that their work was mainly sedentary.

Regarding healthy diet, the mean score showed a moderate level of adherence to daily diet guidelines, in accordance with previous reports [37]. Although it is difficult to compare studies due to different measures [7], low scores for healthy diet maintenance have been generally observed among breast cancer survivors [4, 43]. Regarding diet elements, the figures in the present study were lower than the World Cancer Research Fund/American Institute for Cancer recommendations [8]. In the present study, 57.9% of participants indicated eating four or fewer servings of fruits and vegetables a day, whereas the recommendation is at least five daily servings of nonstarchy vegetables and fruits [8]. High intake of fruits and vegetables is a primary element of a healthy diet and related to better prognostic factors among cancer survivors [8]. However, the present finding indicates higher consumption of fruits and vegetables compared to former studies, for example, in Karavasiloglou and associates’ study [44], cancer survivors indicated eating 2.4 servings of vegetables and 1.0 servings of fruit a day. Regarding whole-grain consumption, in the current study, 53% of participants indicated eating one or no servings of whole grains a day, which is lower than the recommendation to eat whole grains in most meals [8]. Various studies have noted the importance of whole-grain consumption. For example, a meta-analysis found that three daily servings of whole grains lower the risk of mortality from cardiovascular diseases by 25%, all-cause mortality by 17%, and total cancer mortality by 10% [45]. Although previous studies suggested various environmental, demographic, and cancer-related factors and cognitive perceptions and attitudes [9, 15,16,17,18], the present results offer a theoretically based model [21] of associations between coping resources and strategies and healthy lifestyle maintenance, as further discussed.

Following the coping theory [21], healthy lifestyle discrepancy is a cognitive perception that may influence an individual’s emotions and behaviors. Accordingly, this study indicated that the higher the discrepancy between suggested and actual healthy lifestyle maintenance among participants, the less healthy their diet was and the less they engaged in physical activity, an association which can be explained in several ways. This finding may suggest that being aware of this discrepancy may evoke uncomfortable feeling of low self-efficacy and low ability to follow recommendations, which may decrease motivation to engage in healthy behaviors [19]. This explanation accords with the theory of cognitive dissonance [26]. Higher dissonance is often related to avoidance of health-related information [30]. Second, survivors may be less motivated to change their health behaviors [19]. Third, nowadays, cancer survivors can access many different and at times contradictory lifestyle recommendations. Survivors who perceive a discrepancy between their lifestyle and the recommended lifestyle might feel they are always “wrong” due to confusing recommendations, which may lower their motivation to practice a healthy diet. An additional explanation of this finding aligns with previous studies [46] indicating that solely holding information about health behaviors is not enough to motivate healthy lifestyle maintenance. For example, studies found that understanding the importance of routine screening for early cancer detection does not ensure involvement in screening [46], although other studies with populations not affected by cancer found higher cognitive dissonance and increased engagement in a healthy lifestyle [29]. Nevertheless, the association between health discrepancy and healthy lifestyle can be explained in the other direction—that is, cancer survivors who are aware of their unhealthy eating might perceive higher discrepancy.

The study model showed that lifestyle discrepancy was only directly associated with the healthy lifestyle components, and these associations were not mediated via emotion regulation patterns. This finding contrasts with the coping theory [21], which posits that coping mediates the effect of cognitive perceptions on emotional and behavioral outcomes. However, perceived discrepancy had not been previously examined in relation to emotion regulation patterns, other coping strategies, or healthy lifestyle among cancer survivors.

Self-compassion, a major personal resource related to efficient coping with long-term stressors [22, 47], has been seldom studied in relation to health behaviors among cancer survivors [19]. Our study supports previous findings in various populations that self-compassion was positively associated with engagement in health behaviors, including physical activity [25, 47], although others found no associations [48]. This association was previously explained by the positive effect of self-compassion on motivation, overcoming barriers to maintaining a physical activity regimen [49], and efficient coping patterns [22].

In accordance with some previous findings, the present results indicate that cognitive reappraisal was associated with better physical activity [50], whereas expressive suppression usually was related to worse outcomes [51]. This is the first study to the best of our knowledge to show the mediational effect of emotion regulation patterns between self-compassion and physical activity among cancer survivors. Our findings suggest that individuals with high self-compassion tend to acknowledge their hardships and accept them; then, they shift their view of the situation to a more positive or manageable one, as former research found [19, 47, 51]. A previous study supported the negative association between self-compassion and expressive suppression [51], suggesting that coping patterns mediate the relationship between personal resources and emotional and behavioral outcomes [21]. Nevertheless, due to the correlational nature of the results, it may be that higher engagement in physical activity improves self-compassion and enables more adaptive coping patterns.

In contrast to the mediational associations between self-compassion and physical activity, self-compassion was not correlated with healthy diet, neither directly nor indirectly via emotion regulation. This contradicts former findings that self-compassion was correlated with better adherence to a healthy lifestyle [25, 47]. However, these studies were conducted in the general population and assessed healthy eating mainly by asking participants to share their subjective perception of their eating habits [25, 47], which may have been biased by social desirability [52].

The lack of an association between emotional distress and healthy lifestyle contradicts previous findings in the general population [53] and among cancer survivors [6], especially given findings of bidirectional influences between lifestyle and emotional states [53]. The lack of associations may be explained by the low emotional distress reported by the participants that may not affect their health behaviors, as previously reported [17].

These results have several implications for practice. First, our findings suggest that to improve survivors’ lifestyle, interventions should be tailored to address perceptions of discrepancy and strengthen self-compassion and positive emotion regulation strategies. This accords with previous studies that found providing health information or referring survivors to lifestyle consultations may not be sufficient for healthy lifestyle change or long-term maintenance [46]. We suggest identifying cancer survivors with high discrepancy regarding their health behaviors and initiating discussions on ways to reduce this discrepancy using dissonance-based interventions [54]. Further, we encourage health professionals to explore their sense of perceived discrepancy regarding their own lifestyle and how it may influence lifestyle suggestions for clients.

Psychosocial oncology professionals can help cancer survivors strengthen self-compassion and cognitive reappraisal strategies and discuss how challenging yet important it is to adhere to a healthy lifestyle. These could be accomplished by providing simple yet significant self-compassion practices to manage feelings of being overwhelmed, including increased awareness of self-judgment, feelings of inadequacy, and intolerance of disliked personal characteristics, along with mindfulness and acceptance [19]. To achieve this goal, we suggest that professionals adopt intervention techniques from acceptance and commitment therapy or compassion cultivation training models previously adapted for cancer patients [23].

Several limitations of the study should be noted. A main limitation is the cross-sectional design; therefore, caution is needed in inferring the directionality of the results. In addition, the study collected data online. Therefore, breast cancer survivors who have lower access to the internet or social media might not have been able to participate in the study, which may limit the study’s generalizability to other breast cancer survivors. Another limitation of the data collection method is that participants reported their health- and cancer-related history. Further, because scales measuring cognitive dissonance in relation to healthy lifestyle are lacking, one item was composed to measure perceived lifestyle discrepancy. Further validation of this item is warranted. Due to social desirability, participants may have answered questions in accordance with their desired lifestyle choices rather than actual choices. Nevertheless, this study is among a few to examine psychological variables that may directly and indirectly influence the maintenance of a healthy lifestyle, which is critical for quality of life and survival among breast cancer survivors. Further research is needed regarding factors that affect healthy lifestyle maintenance, such as body compassion [23], and development and validation of a perceived discrepancy questionnaire for cancer survivors. Finally, further examining factors associated with healthy lifestyle among survivors of breast and other cancers with longitudinal or ecological momentary designs is suggested.