Background: Consuming a balanced diet and regular activity have health benefits. However, many adults have a difficult time adhering to diet and activity recommendations, especially in lifestyle interventions. Adherence to recommendations could be improved if common facilitators and barriers are accounted for in intervention design. The aim of this systematic review was to understand perceived barriers and facilitators to lifestyle (diet and/or activity) intervention guidelines. Methods: This review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Studies included relied on qualitative methods to explore the barriers and facilitators healthy adults ( $$\ge$$≥ 18 years) experienced in lifestyle interventions. Google Scholar, Cochrane Reviews, Medline, PubMed, and Web of Science were searched from January 2005 to October 2021. Main themes from each paper were thematically analyzed and reported as a barrier or facilitator to adherence at the individual, environment or intervention level using inductively derived themes. Study quality was assessed using the Critical Appraisal Skills Programme. Results: Thirty-five papers were included. Of these, 46% were conducted in North America and the majority had more female participants (86% in mixed-sex studies, 26% females only). Similar themes emerged across all three levels as facilitators and barriers. At the individual level, attitudes, concern for health and physical changes. At the environmental level, social support, social accountability, changeable and unchangeable aspects of the community. Finally, delivery and design and content at the intervention level. An additional facilitator at the intervention level included fostering self-regulation through Behavior Change Taxonomies (BCT). Conclusions: Lifestyle interventions that foster self-regulatory skills, opportunities for social engagement and personalization of goals may improve behaviour adherence. This can be achieved through inclusion of BCT, tapering off of intervention supports, identification of meaningful goals and anticipated barriers with participants.

Background: Accurate dietary assessment is needed in studies that include analysis of nutritional intake. Image-based dietary assessment apps have gained in popularity for assessing diet, which may ease researcher and participant burden compared to traditional pen-to-paper methods. However, few studies report the validity of these apps for use in research. Keenoa is a smartphone image-based dietary assessment app that recognizes and identifies food items using artificial intelligence and permits real-time editing of food journals. Objective: This study aimed to assess the relative validity of an image-based dietary assessment app — Keenoa — against a 3-day food diary (3DFD) and to test its usability in a sample of healthy Canadian adults. Methods: We recruited 102 participants to complete two 3-day food records. For 2 weeks, on 2 non-consecutive days and 1 weekend day, in random order, participants completed a traditional pen-to-paper 3DFD and the Keenoa app. At the end of the study, participants completed the System Usability Scale. The nutrient analyses of the 3DFD and Keenoa data before (Keenoa-participant) and after they were reviewed by dietitians (Keenoa-dietitian) were analyzed using analysis of variance. Multiple tests, including the Pearson coefficient, cross-classification, kappa score, % difference, paired t test, and Bland-Altman test, were performed to analyze the validity of Keenoa (Keenoa-dietitian). Results: The study was completed by 72 subjects. Most variables were significantly different between Keenoa-participant and Keenoa-dietitian (P<.05) except for energy, protein, carbohydrates, fiber, vitamin B1, vitamin B12, vitamin C, vitamin D, and potassium. Significant differences in total energy, protein, carbohydrates, % fat, saturated fatty acids, iron, and potassium were found between the 3DFD and Keenoa-dietitian data (P<.05). The Pearson correlation coefficients between the Keenoa-dietitian and 3DFD ranged from .04 to .51. Differences between the mean intakes assessed by the 3DFD and Keenoa-dietitian were within 10% except for vitamin D (misclassification rate=33.8%). The majority of nutrients were within an acceptable range of agreement in the Bland-Altman analysis; no agreements were seen for total energy, protein, carbohydrates, fat (%), saturated fatty acids, iron, potassium, and sodium (P<.05). According to the System Usability Scale, 34.2% of the participants preferred using Keenoa, while 9.6% preferred the 3DFD. Conclusions: The Keenoa app provides acceptable relative validity for some nutrients compared to the 3DFD. However, the average intake of some nutrients, including energy, protein, carbohydrates, % fat, saturated fatty acids, and iron, differed from the average obtained using the 3DFD. These findings highlight the importance of verifying data entries of participants before proceeding with nutrient analysis. Overall, Keenoa showed better validity at the group level than the individual level, suggesting it can be used when focusing on the dietary intake of the general population. Further research is recommended with larger sample sizes and objective dietary assessment approaches.

Background: Boys' and girls' food habits diverge in adolescence (13–18 years). This contributes to unequal risks of adverse health outcomes based on sex and gender in adulthood (e.g., heart diseases in men vs. disorder eating in women). Though multi-factorial, why these dietary differences occur is unclear.Purpose: To identify the reasons why adolescents' motivation behind dietary habits differs among genders.Methods: Four databases were searched following PRISMA guidelines. Eligible studies had to use qualitative methodology and report at least one gender unique theme. Reported themes were thematically analyzed, with a sub-analysis by country where the studies were conducted. Quality appraisals were assessed using the Critical Appraisal Skills Programme checklist.Results: In the 34 eligible articles (n= 1,694 returned) two overarching themes emerged that dictated dietary habits in adolescents: Self-motivators and Uncontrollable factors. Gender differences arose whereby girls highlighted more external motivators (e.g., eat healthier, change dietary habits around boys and be thin to fit traditional norms) over their dietary habits. In contrast, boys focused on more internal motivators (e.g., gain autonomy, eat for enjoyment and pursue gains in physical performance). This suggests that motivation underlying how boys and girls eat differs. These trends were largely consistent across countries.Conclusion: Boys' and girls' food habits are not motivated by the same factors. To create more effective dietary interventions targeting health promotion, unique motivations behind food habits need to be understood and incorporated.Systematic review registration: Identifier: CRD42022298077.

The current study aimed to test the factor structure of the Adult Eating Behavior Questionnaire (AEBQ), its construct validity against the Three-Factor Eating Questionnaire (TFEQ-R18) and its associations with body mass index (BMI) in Canadian adults (n = 534, 76% female). Confirmatory factor analysis (CFA) revealed that a seven-factor AEBQ model, with the Hunger subscale removed, had better fit statistics than the original eight-factor structure. Cronbach’s alpha was used to assess the internal reliability of each subscale and resulted with α > 0.70 for all subscales except for Hunger (α = 0.68). Pearson’s correlations were used to inform the convergent and discriminant validation of AEBQ against the TFEQ-R18 and to examine the relationship between AEBQ and BMI. All AEBQ Food Approach subscales positively correlated with that of the TFEQ-R18 Emotional Eating and Uncontrolled Eating subscales. Similarly, BMI correlated positively with Food Approach subscales (except Hunger) and negatively with Food Avoidance subscales (except Food Fussiness). These results support the use of a seven-factor AEBQ for adults self-reporting eating behaviors, construct validity of the AEBQ against TFEB-R18, and provide further evidence for the association of these traits with BMI.

Background: Weight loss increases survivorship following breast cancer diagnosis. However, most breast cancer survivors (BCS) do not meet diet and exercise recommendations.Aim: The purpose of this study was to explore the barriers and facilitators of BCS who had lymphedema and who participated in a 22‐week weight loss lifestyle intervention.Methods and results: Participants completed semi‐structured interviews about barriers and facilitators to intervention adherence. Interviews were transcribed verbatim and a thematic analysis was conducted. Participants (n = 17) were 62 ± 8.0 years of age with a mean body mass index of 34.0 ± 7.1 kg/m². Four themes emerged: (1) facilitators of intervention adherence, (2) barriers of intervention adherence, (3) continuation of healthy habits post intervention, and (4) recommendations for intervention improvements. Facilitators of intervention adherence were education, social support, routine, motivation, goal‐setting, meal‐provisioning, self‐awareness, and supervised exercise. Barriers to intervention adherence were personal life, health, meal dissatisfaction, seasonality, unchallenging exercises, and exercising alone. All women planned to continue the acquired healthy habits post intervention. Recommendations to improve the study included addressing the exercise regime, meal‐provisioning, and dietary intake monitoring methods.Conclusion: Future strategies to engage BCS in weight loss interventions should promote group exercise, offer individualized meal‐provisioning and exercise regimes, provide transition tools, and allow participants to choose their self‐monitoring method.