The mediating role of recreational physical activity and dietary behavior in the relationship between family affluence and mental well-being: an interventional effects approach.

There is evidence that low levels of physical activity and unhealthy dietary behaviours are associated with poor health in adolescents, leading to an increased risk of chronic disease in adulthood. These behaviours are modifiable and since adolescents spend a significant amount of time in school this provides an increasingly popular setting for physical activity and dietary interventions. A systematic review of school-based interventions aimed at changing physical activity and/or dietary behaviours in adolescents (11‐18yrs) published between 1995 and 2008 was conducted. The aim was to identify successful interventions, assess the quality of reporting, identify the effective components and any specific behaviour change theories and techniques implemented which may have facilitated interventions success. From 274 studies identified 15 were included in the review; two dietary only, seven physical activity only and six physical activity combined with dietary interventions. There were insufficient studies (n = 2) to assess fully the effectiveness of school based diet only interventions. The success of school based interventions aimed at changing both physical activity and dietary behaviours of adolescents was mixed. There was some evidence of gender differences with boys increasing physical activity behaviours only and girls improving dietary behaviours only. Interventions aimed at only physical activity behaviours were the most successful, with multi-component interventions which included an educational and environmental component identified as being most effective. Physical activity only interventions aimed and tailored specifically for girls were generally successful at improving physical activity behaviours. Interventions aimed at improving physical activity behaviours and aimed at both boys and girls tended to be more effective at improving the physical activity behaviours of boys only. There was little evidence that parental involvement facilitated interventions success. No one behavioural theory was clearly identified as being associated with studies reporting significant results for either dietary or PA behaviours. Studies that were based on a theory which considered the environmental influences on behaviour, such as Social Cognitive Theory (1) , however, appeared more effective. There were no specific behaviour change techniques identified with studies reporting significant results. The most common behaviour change techniques implemented in interventions were Prompt practice and Stimulating social support/norm in family and/or community for physical activity behaviours with the addition of Provided knowledge about target behaviour for dietary behaviours for dietary behaviours. Overall the reporting of intervention design and methodology was generally of moderate quality. The heterogeneity of the studies made it difficult to generalise which interventions were most effective, but there was a suggestion that combined education and environmental interventions were effective at changing physical activity behaviours in both boys and girls. The quality of study reporting needs to improve to identify the active components and behaviour change techniques implemented within interventions to facilitate the replication of interventions in the future.

We investigate the relationship between family affluence, an indicator of socio-economic status, and the mental well-being of approximately 20,000 children and young adults in Flanders, using data from the Health Behaviour in School-aged Children (HBSC) study. To understand this relationship, we assess the mediating roles of physical activity and dietary behavior.Traditional mediation analysis approaches, such as the parallel mediation model within the Baron and Kenny framework, have been criticized for producing path-specific effects that lack clear causal interpretation. In contrast, the counterfactual framework for causal inference introduced natural direct and indirect effects, enhancing clarity around the assumptions required for effect identification. However, natural effects face practical limitations: they may provide limited insights into real-world interventions and are difficult to identify when multiple mediators share unmeasured common causes or when the causal structure is unclear.In this paper, we address these challenges using interventional direct and indirect effects, which require fewer assumptions for identification and offer greater relevance for policy interventions. Our analysis demonstrates robust evidence for the mediating role of physical activity in the association between family affluence and mental well-being. In contrast, the mediating role of dietary behavior is less substantiated. These findings indicate that interventions aimed at enhancing physical activity among children and young adolescents with low socio-economic status could potentially improve their mental well-being.

Cross-sectional associations between maternal self-efficacy and dietary intake and physical activity in four-year-old children of first-time Swedish mothers

There is a lack of validated measures of parental self-efficacy (PSE) covering both physical activity and dietary behaviors in children which can be used to prevent childhood obesity. This study developed a new measure of PSE for promoting healthy physical activity and dietary behaviors in children and assessed its psychometric properties. Participants were mothers (n = 2,232) with 3-year-old first-born children living in Stockholm, Sweden. The mothers responded to questionnaires measuring PSE, locus of control, and self-esteem. Exploratory factor analysis yielded a three-factor structure, interpreted as PSE for promoting healthy dietary behaviors in children (Factor 1), PSE for limit-setting of unhealthy dietary or physical activity behaviors in children (Factor 2), and PSE for promoting healthy physical activity behaviors in children (Factor 3). The factor model was supported by confirmatory factor analysis. The internal consistency and test-retest reliability of the new PSE measure were high; discriminant validity was adequate. The Parental Self-Efficacy for Promoting Healthy Physical Activity and Dietary Behaviors in Children Scale (PSEPAD) shows promise as a valuable instrument in childhood obesity prevention.

It has been estimated that unhealthy diet and physical inactivity are responsible for 15% and 9% of premature deaths, respectively. These lifestyle behaviours can modulate biomedical risk factors of non-communicable diseases (NCDs), which are the leading cause of death in all developed countries. The importance of healthy diet and physical activity (PA) behaviours for reducing the risk of NCDs is well known, but changing these behaviours is complex and challenging. The workplace can be both an environment that challenges lifestyle behaviours, or an ideal setting to promote these. Nurses have a stressful occupation, in which shift patterns and job demands promote irregular eating patterns, frequent energy-dense snacking, fatigue and inactivity. In addition, 60% of nurses are overweight or obese. The nursing workforce in Australia is aging, with 28% of nurses being over the age of 50 compared with the average 15% in other workforces. Age, job demands and lifestyle behaviours make it clear that nurses are at increased risk for NCDs. Poor health in nurses can lead to loss of productivity and increased health care costs, which can compromise quality of care. However, little is known on how to improve nurses’ lifestyle behaviours, with the literature showing inconclusive results on the effectiveness of specific strategies to promote such behaviours. There is a clear need for additional studies that are designed using a rigorous and systematic approach which is underpinned by established behaviour change theory. The Intervention Mapping (IM) framework is an example of such an approach. The aim of this thesis is to address this gap in knowledge and add to the literature by developing, implementing and evaluating an intervention using the IM framework. This is among the first studies to undertake a comprehensive process for the development, implementation and evaluation of a workplace intervention designed to promote diet and PA behaviours in nurses. A systematic review of diet and PA interventions for nurses was conducted, as first part of the Needs Assessment (NA) of the target group. Nine intervention studies with a total of 737 participants were included in the review. Results indicated a modest increase in some measures of PA and a positive effect on participants’ body mass index and body composition, but results for other outcomes were inconsistent between studies. Intervention strategies that assisted with promoting behaviour change in nurses included pedometers, step challenges, and nurse champions. However, studies often used tools that were not validated or self-report to measure intervention outcomes. Studies provided little rationale for study design, and/or lacked a theoretical framework. The review identified a relative paucity of diet and PA interventions for nurses in the literature and highlighted a clear need for more and better-designed studies. The second part of the NA included a qualitative study with nurses who were potential participants for the intervention study. Using focus group interviews, I explored participants’ determinants for diet and PA behaviours, and consulted with them about intervention design and materials. Results suggested that lack of breaks and consequent hunger dictated nurses’ diet behaviour, while fatigue and lack of time undermined PA behaviour. Nurses described a desirable intervention as a simple program that could help them monitor their diet and PA, set goals, and receive social support from colleagues. The NA informed the intervention development, the rational for behaviour change theory and materials selection, study design, and outcome measures. A 3-month intervention was implemented to evaluate changes in diet and PA. The main outcome measures were diet quality, average daily steps, and patterns of PA. Results indicated a significant improvement on fruit and vegetable consumption (+4% daily energy intake), at the end of the intervention. . However, at the same time-point, the percentage of total time spent on MVPA significantly decreased from 3.0 to 2.5%, and average daily steps decreased from 8435 to 7929. Following the intervention implementation and evaluation, process and economic evaluations were conducted to analyse the scalability of this intervention. The process evaluation followed the RE-AIM framework and aimed to shed light on the observed intervention outcomes and explain the contradictory results. Findings showed that materials were not adopted as planned, and that there was a mismatch on what participants desired in the intervention and what they were actually ready to do and use. Participants also discussed their difficulty to change both behaviours at once, with the majority finding it easier to focus on diet only. The economic analysis calculated the costs for intervention delivery and participation, and cost-effectiveness of each intervention outcome. Results indicated that only dietary outcomes were cost-effective, but in its current shape the intervention’s small effects make it difficult to define stakeholders’ willingness to pay. Nurses are at risk for NCD because of their poor diet and PA behaviours; however, the promotion of such behaviours in this group remains very difficult because they are an extremely hard-to-reach group. This challenged recruitment, engagement and retention, leading to a small sample size and modest change in diet and PA outcomes in this study. Hospital management involvement and advocacy for workplace health promotion interventions is mandatory to ensure a better reach in future studies. Such involvement could facilitate work environment manipulation, such as better shift pattern or provision of healthy snacks, and selection of paid nurse champions who encourage colleagues and ensure intervention’s implementation and maintenance.

BackgroundThe rapid development of artificial intelligence technology has enabled chatbots to increasingly promote health-related behaviors, addressing the high demand for human resources in traditional interventions. Several systematic reviews have been conducted in this area. However, the existing reviews have not focused on the rigorously designed randomized trials of the state-of-the-art chatbots (interacting with users through unconstrained natural language), thus calling for an updated review.ObjectiveWe aimed to explore the effects of natural language processing (NLP) chatbot–based interventions on improving diet, physical activity, and tobacco smoking behaviors in the general population and to evaluate the chatbot use behaviors during the implementation process.MethodsWe comprehensively searched 12 databases or registers for eligible studies published from January 1, 2010, until July 16, 2024, and obtained a total of 6301 studies. We included randomized controlled trials (RCTs) that used NLP-chatbots to promote diet, physical activity, or tobacco smoking behaviors among adults or children. Due to considerable heterogeneity across the included studies, we adopted the synthesis without meta-analysis guidelines and summarized the effectiveness of NLP chatbot–based interventions. We used the new evidence-mapping method (bubble plot) to visualize the results. We also described the results related to the changes in diet, physical activity, or tobacco smoking behaviors (eg, change of BMI and stage of change). To evaluate the implementation process of the intervention, we summarized users’ interaction with NLP-chatbots and their feelings (eg, satisfaction) about NLP-chatbot use. Additionally, we assessed the risk of bias of studies using the RoB 2.0 (Risk of Bias; The Cochrane Collaboration) tools.ResultsWe finally included 7 RCTs. Concerning dietary and physical activity behaviors, the effectiveness of NLP chatbot–based interventions was inconsistent among adults, while no evidence of effect was observed among children. Concerning tobacco smoking behaviors, the included studies showed consistent evidence of improving this behavior among adults. Regarding the risk of bias of the changes in diet, physical activity, and tobacco smoking behaviors, 2 of 3, 2 of 4, and 1 of 2 studies had a high risk of bias, respectively, while the remaining had a low risk of bias. Concerning the interactions with NLP-chatbots, studies showed an overall high percentage of general interaction between users and NLP-chatbots, but not a satisfactorily high percentage of interactions specific to health behaviors. Concerning feelings about NLP-chatbot use, users showed a positive impression of NLP-chatbot use, feeling it was useful, credible, and financially feasible.ConclusionsNLP chatbot–based interventions were beneficial for adults’ tobacco smoking behaviors, but no such evidence was found on diet or physical activity behaviors among adults or children. More RCTs with larger samples and lower risk of bias are urgently needed to enhance our findings in the future.

BackgroundRecent studies have shown the potential of Web-based interventions for changing dietary and physical activity (PA) behavior. However, the pathways of these changes are not clear. In addition, nonusage poses a threat to these interventions. Little is known of characteristics of participants that predict usage.ObjectiveIn this study we investigated the users and effect of the Healthy Weight Assistant (HWA), a Web-based intervention aimed at healthy dietary and PA behavior. We investigated the value of a proposed framework (including social and economic factors, condition-related factors, patient-related factors, reasons for use, and satisfaction) to predict which participants are users and which participants are nonusers. Additionally, we investigated the effectiveness of the HWA on the primary outcomes, self-reported dietary and physical activity behavior.MethodsOur design was a two-armed randomized controlled trial that compared the HWA with a waiting list control condition. A total of 150 participants were allocated to the waiting list group, and 147 participants were allocated to the intervention group. Online questionnaires were filled out before the intervention period started and after the intervention period of 12 weeks. After the intervention period, respondents in the waiting list group could use the intervention. Objective usage data was obtained from the application itself.ResultsIn the intervention group, 64% (81/147) of respondents used the HWA at least once and were categorized as “users.” Of these, 49% (40/81) used the application only once. Increased age and not having a chronic condition increased the odds of having used the HWA (age: beta = 0.04, P = .02; chronic condition: beta = 2.24, P = .003). Within the intervention group, users scored better on dietary behavior and on knowledge about healthy behavior than nonusers (self-reported diet: χ2 2 = 8.4, P = .02; knowledge: F1,125 = 4.194, P = .04). Furthermore, users underestimated their behavior more often than nonusers, and nonusers overestimated their behavior more often than users (insight into dietary behavior: χ2 2 = 8.2, P = .02). Intention-to-treat analyses showed no meaningful significant effects of the intervention. Exploratory analyses of differences between pretest and posttest scores of users, nonusers, and the control group showed that on dietary behavior only the nonusers significantly improved (effect size r = −.23, P = .03), while on physical activity behavior only the users significantly improved (effect size r = −.17, P = .03).ConclusionsRespondents did not use the application as intended. From the proposed framework, a social and economic factor (age) and a condition-related factor (chronic condition) predicted usage. Moreover, users were healthier and more knowledgeable about healthy behavior than nonusers. We found no apparent effects of the intervention, although exploratory analyses showed that choosing to use or not to use the intervention led to different outcomes. Combined with the differences between groups at baseline, this seems to imply that these groups are truly different and should be treated as separate entities.Trial registrationTrial ID number: ISRCTN42687923; http://www.controlled-trials.com/ISRCTN42687923/ (Archived by WebCite at http://www.webcitation.org/5xnGmvQ9Y)

According to social cognitive theory, self-efficacy is central to behavior change. Consequently, parental self-efficacy (PSE) for influencing children's dietary, physical activity (PA), sedentary, and screen time behaviors is important for child obesity prevention. The aim of this study was to evaluate the psychometric properties of an instrument to measure PSE regarding these behaviors in disadvantaged areas. Parents ( n = 229) of whom 47% had completed secondary school or less, and who participated in the Healthy School Start trial, responded to a 15-item PSE instrument. Children's diet and screen time were measured through parent reports. PA and sedentary behaviors were measured using accelerometers. Construct validity was assessed using exploratory factor analysis (EFA), criterion validity by correlations with child behaviors, and internal consistency by Cronbach's alpha. The EFA yielded three factors: (a) PSE for promoting PA; (b) PSE for limiting intake of unhealthy foods, unhealthy drinks, and screen time; and (c) PSE for promoting intake of fruits and vegetables, all with acceptable to good internal consistency (α = .77-.81). Significant correlations ( p < .01) were found between children's dietary ( rs = -.19 to -.29) and screen time ( r = -.29) behaviors and Factor 2, and dietary behaviors and Factor 3 ( rs = .20-.39) but not regarding PA and sedentary behaviors and Factor 1. The instrument demonstrated good construct validity and acceptable to good internal consistency regarding all but PA behaviors. It may be useful for assessing PSE in child obesity prevention interventions in disadvantaged settings after some refinement.

Body Image and Self-Esteem among Adolescents Undergoing an Intervention Targeting Dietary and Physical Activity Behaviors

Purpose: This study was conducted to specify the differences in nutrition knowledge, dietary behaviors, physical activity, and self-efficacy behaviors based on obesity status among adolescents.Methods: In the study, descriptive-correlational design type was used. The sample of the study consisted of 530 adolescents and their parents selected among 5th grade students studying in five secondary schools by using the stratified random sampling method. The study data were collected using the Family Information Questionnaire, the Nutrition Knowledge Scale,the Diet Behavior Scale,the Children’s Dietary Self-Efficacy Scale and the Exercise Behavior Scale. Adolescents were assessed according to body mass index percentages in overweight - obese and normal weight groups in two groups. SPSS 22 program was used in the analysis of the data. For the data assessment, descriptive statistical methods (mean, median, number, percentage) were used. Pearson’s Chi-Square test was applied for comparison of categorical data. The t-test was performed in between-group comparison of parameters. Results: 50.9% of the adolescents were male and 30% of them n=(159) were found to be overweight and obese according to BMI. There was no significant difference between the BMI normal, and overweight/obese adolescents according to gender, age, income status and the mother’s educational level (p&gt;0.05). The difference between BMI normal and overweight/obese children based on Father’s Educational Level, Mother’s BMI, and Father’s BMI values was significant. As educational level of the father and BMI value of mother and father increased, the rate of overweight-obese adolescents also increased (p&lt;0.05). It was found that adolescents’ mean “physical activity behaviors” was 17.457 ± 3.732; “nutrition knowledge mean score” was 11,330 ± 3,258; “dietary self-efficacy” mean score was 5.138 ± 5.386; “dietary behavior” mean score was 3.694 ± 5.324. The adolescents’ physical activity behaviors were high, self-efficacy behaviors were good, and nutrition knowledge levels and dietary behaviors were at moderate level. Nutrition knowledge, dietary behaviors, and dietary self-efficacy of overweight and obese adolescents were found to be high (p&lt;0.05). No significant difference was found among the groups based on physical activity behaviors (p&gt;0.05). Conclusion: All adolescents' nutritional knowledge and nutritional behavior scores were moderate. Nutrition knowledge, nutritional behavior and nutrition self-efficacy scores were high in overweight / obese adolescents. This result may be due to the fact that adolescents and parents in the overweight and obese group are more cautious about nutritional behavior. It can be said that obese adolescents can not turn into information behaviors. Attempts can be made for this. In this regard, larger studies can be suggested.

BackgroundParental self-efficacy (PSE) has been suggested as a key factor for enabling parents to support children in the development of healthy dietary and physical activity behaviors and to prevent childhood obesity. However, studies of intervention effects on PSE are lacking. The present study involved a secondary analysis of data on PSE collected in a previous primary prevention trial of childhood obesity called the PRIMROSE trial. The trial involved a family-based intervention using motivational interviewing and principles of cognitive-behavioral therapy within a social-cognitive theory framework.MethodsIn the PRIMROSE trial, parents and their children were randomly allocated to the intervention or usual care. In the present study, 928 mothers who responded to the Parental Self-Efficacy for Promoting Healthy Physical Activity and Dietary Behaviors in Children Scale (PSEPAD) at follow-up assessment were included. Data were analyzed using linear regression based on generalized estimating equations, with adjustment made for PSE at baseline.ResultsAt follow-up assessment, there was a statistically significant difference of 1.4 units, 95% CI [0.4, 2.4], p = 0.009, between the intervention and control conditions on the subscale of the PSEPAD concerning PSE for promoting healthy dietary behaviors in children. However, this difference was deemed as without clinical importance. On the total scale or other subscales of the PSEPAD there were no statistically significant differences in PSE between conditions.ConclusionsThere was a statistically significant, but not clinically meaningful, intervention effect on PSE. However, because previous research repeatedly has shown positive associations of PSE with dietary and physical activity behaviors in children and that self-efficacy mediates behaviors, the construct may be important for influencing dietary and physical behaviors in children. Therefore, more research is warranted evaluating the effects of interventions on PSE in the context of childhood obesity prevention.Trial registrationRetrospectively registered 9 October 2013 at ISRCTN (ISRCTN16991919).

Review Question/Objective The primary objective of this review is to identify the effectiveness of web-based interventions on weight loss and maintenance. The second objective is to identify the effectiveness of web-based interventions on behaviours associated with weight loss (eating and physical activity). The third objective is to identify what components of web-based interventions are associated with greater weight loss and maintenance, as well as lower attrition rates. Criteria for Inclusion Types of participants The quantitative component of this review will consider studies that include overweight and/or obese adults, aged greater than 18 years. Overweight and obesity will be defined as a body mass index (BMI) greater than or equal to 25(kg/m2). Types of intervention(s) The quantitative component of the review will consider studies that evaluate web-based interventions with the primary aim of achieving weight loss or weight maintenance following weight loss. This includes studies with the aim of achieving positive dietary and physical activity behaviour change for participants that include overweight/obesity outcome measures. However, if the stated aim is to achieve positive dietary and physical activity behaviour change for participants, and they do not include overweight/obesity outcome measures they will be excluded. At least one arm of the study must include a web-based intervention. A web-based intervention will be based around a website that participants receive information from and directly interface with. They are not required to input information into the website for the intervention to be included. Types of outcomes This review will consider studies that include the following outcome measures: Primary Outcome: Overweight/obesity related outcomes: weight (kg), % body weight lost, BMI, waist measurements, % body fat, % lost 5% of body weight. Secondary Outcomes: Dietary behaviours: energy intake, core food group intake (e.g. number of serves of fruit per day), macronutrient composition of diet (e.g. fat intake per day) Physical activity behaviours: energy expenditure, time spent in activity, steps per day. Effect modifiers/confounders: Compliance/engagement with website: website logins, completion of self-monitoring diaries, attendance at meetings/group discussions, retention etc Adjuncts to web-based intervention (e.g. contact with professional/face to face contact, other eHealth technology such as SMS, email, CD-Rom, Personal Digital Assistant (PDA) and use of rewards/prizes) Intervention based on theoretical models Intensity of web-based intervention: type and number of features included (e.g. self-monitoring diary, chat room, discussion board)

BackgroundThe relationship between colorectal cancer (CRC) risk and physical activity and dietary habits has been well-established, but less is known about the relationship between these behaviours and quality of life (QOL) post-diagnosis. Moreover, it is unknown whether this relationship is consistent across cancer stage or treatment setting. Thus, the purpose of this study was to assess current diet and physical activity behaviour in CRC survivors receiving systemic chemotherapy, and to examine potential associations between these behaviours and quality of life. A secondary purpose was to examine the association between social support, diet, and physical activity behaviour in this population.MethodsUsing a cross-sectional survey, 67 CRC survivors currently receiving chemotherapy in Calgary, Alberta completed the survey package. Measures included demographic and medical data, physical activity levels, diet behaviour, QOL, and social support.ResultsIn a largely metastatic sample (63%), approximately half were meeting national dietary guidelines (58%), less were meeting national physical activity guidelines (26%), and a small number were meeting both (17%). However, only 12.3% (n = 8) reported completely sedentary behaviour, and 7 of these 8 participants were receiving metastatic treatment. Neither behaviour was significantly associated with QOL or perceived social support. Furthermore, there were no significant QOL differences between those treated with palliative intent or adjuvant therapy. Important group differences emerged between those meeting and not meeting the guidelines, and associations between QOL, age, BMI, and provisions of social support.ConclusionThese findings provide insight into lifestyle behaviours of CRC survivors currently receiving systemic chemotherapy, and the differences in perceived QOL as affected by severity of disease and treatment setting. Prospective studies in a larger sample of CRC survivors on chemotherapy are needed to confirm lifestyle behaviour patterns and identify factors related to QOL that are unique to this population, especially during metastatic treatment.

BackgroundThe potential synergistic effects of multiple dietary and physical activity behaviours on the risk of chronic conditions and health outcomes is a key issue for public health. This study examined the prevalence and clustering patterns of multiple health behaviours among a sample of adolescents in the UK.MethodsCross-sectional survey of 176 adolescents aged 12–16 years (49% boys). Adolescents wore accelerometers for seven days and completed a questionnaire assessing fruit, vegetable, and breakfast consumption. The prevalence of adolescents meeting the physical activity (≥ 60 minutes moderate-to-vigorous physical activity/day), fruit and vegetable (≥ 5 portions of FV per day) and breakfast recommendations (eating breakfast on ≥ 5 days per week), and clustering patterns of these health behaviours are described.ResultsBoys were more active than girls (p < 0.001) and younger adolescents were more active than older adolescents (p < 0.01). Boys ate breakfast on more days per week than girls (p < 0.01) and older adolescents ate more fruit and vegetables than younger adolescents (p < 0.01). Almost 54% of adolescents had multiple risk behaviours and only 6% achieved all three of the recommendations. Girls had significantly more risk factors than boys (p < 0.01). For adolescents with two risk behaviours, the most prevalent cluster was formed by not meeting the physical activity and fruit and vegetable recommendations.ConclusionMany adolescents fail to meet multiple diet and physical activity recommendations, highlighting that physical activity and dietary behaviours do not occur in isolation. Future research should investigate how best to achieve multiple health behaviour change in adolescent boys and girls.

PurposeLittle is known about how to improve and create sustainable lifestyle behaviors of cancer survivors. Interventions based on social cognitive theory (SCT) have shown promise. This review examined the effect of SCT-based physical activity and nutrition interventions that target cancer survivors and identified factors associated with their efficacy.MethodsA systematic search of seven databases identified randomized controlled trials that (i) targeted adult cancer survivors (any point from diagnosis); (ii) reported a primary outcome of physical activity, diet, or weight management; and (iii) included an SCT-based intervention targeting physical activity or diet. Qualitative synthesis and meta-analysis were conducted. Theoretical constructs and intervention characteristics were examined to identify factors associated with intervention efficacy.ResultsEighteen studies (reported in 33 publications) met review inclusion criteria. Meta-analysis (n = 12) revealed a significant intervention effect for physical activity (standardized mean difference (SMD) = 0.33; P < 0.01). Most studies (six out of eight) that targeted dietary change reported significant improvements in at least one aspect of diet quality. No SCT constructs were associated with intervention effects. There were no consistent trends relating to intervention delivery method or whether the intervention targeted single or multiple behaviors.ConclusionsSCT-based interventions demonstrate promise in improving physical activity and diet behavior in cancer survivors, using a range of intervention delivery modes. Further work is required to understand how and why these interventions offer promise for improving behavior.Implications for Cancer SurvivorsSCT-based interventions targeting diet or physical activity are safe and result in meaningful changes to diet and physical activity behavior that can result in health improvements.