Background Previous research studies have demonstrated a relationship between low levels of physical activity and high amounts of screen time in children and adolescents. However, this is usually based on self-reported data. Therefore, the aim of this cross-sectional study was to investigate the association between objectively measured smartphone screen time and physical activity among children and adolescents aged 10–15 years. Methods During seven consecutive days, we objectively assessed smartphone screen time, using the SCRIIN smartphone application, and physical activity, using the SCRIIN activity tracker, in children and adolescents recruited from two schools in Stockholm County, Sweden. Moreover, the children/adolescents and their parents responded to a questionnaire, obtaining among other things: self-reported screen time, physical activity, sleep and health-related quality of life. Results A total of 121 children and adolescents (mean age: 12.1 ± 1.5) were included in the study. Objectively measured smartphone screen time was 161.2 ± 81.1 min/day. Mean physical activity, measured with the SCRIIN activity tracker, was 32.6 ± 16.5 active min/day. Minutes of screen time and physical activity did not differ between the children and adolescents from the two schools, despite located in different socioeconomic areas. Further, we found no association between smartphone screen time and physical activity. However, girls aged 14–15 years, had more smartphone screen time (p<0.01) and were significantly more physically active (p<0.01) than girls aged 10–12 years. In addition, boys reported more than five times more time spent on computer and video games than girls did. Conclusion Smartphone screen time was not associated with physical activity level among children and adolescents aged 10–15 years.

Background Adolescents and young adults around the world experience high rates of weight gain. The underlying eating behaviours that may lead to overconsumption of energy are complex and can depend on a number of factors. The aim of this study was to explore if eating behaviour among adolescents and young adults referred to specialized obesity treatment differed depending on sex, body composition, and parental country of birth. Methods Adolescents and young adults aged 16–25 years, referred for obesity treatment in 2018–2021 were included in the study. Eating behaviour was assessed using the Three Factor Eating Questionnaire, comprising domains of uncontrolled-, emotional- and cognitive restraint eating. Student’s t-test was used to compare differences in eating behaviour scores between males and females, and between those having at least one parent born in a Nordic country and those with both parents born outside the Nordic countries. Associations between BMI, waist circumference, and body fat percentage, and eating behaviour as the dependent variable, were examined using linear regression. Results A total of 463 participants, mean age 21 years and mean BMI 41.3 kg/m2, were included in the analysis. Females scored statistically significantly higher than males on emotional eating (45.8 vs. 35.4, p = 0.002) and cognitive restraint eating (45.4 vs. 39.2, p = 0.009). Participants with at least one parent born in a Nordic country reported a statistically significantly lower score of uncontrolled eating (45.7 vs. 51.3, p = 0.02) compared to participants with both parents born outside the Nordic countries. Further, there were statistically significant inverse associations between cognitive restraint eating scores and BMI (β=-0.64, 95%CI: -0.97 to -0.31), waist circumference (β=-0.44, 95%CI: -0.61 to -0.27) and body fat percentage (β=-0.57, 95%CI: -1.01 to -0.14) in models adjusted for age, sex, smoking, and civil status. Conclusion Our findings suggest that sex and parental country of birth may influence eating behaviours among adolescents and young adults referred for specialist obesity treatment. We also found that cognitive restraint eating decreased with increasing BMI, waist circumference, and body fat percentage. This indicates that there may be an inverse association between the ability to restrain oneself from eating and gaining weight, however, the direction of the association must be investigated further. Increased knowledge about eating behaviours may be valuable in the clinical setting.

Background A healthy diet and a sufficient amount of physical activity are important factors to reduce complications of type 2 diabetes. Diet and physical activity are associated behaviours. Individuals who are physically active have also been shown to have healthier eating habits than sedentary individuals. We aimed to evaluate the indirect effect of a smartphone-based physical activity intervention on dietary habits in patients with type 2 diabetes. Methods We performed analyses of secondary outcomes in a randomized controlled trial. The active intervention was use of a smartphone application to promote physical activity during 12 weeks. Dietary intake was assessed at baseline and after three months using a validated semi-quantitative food frequency questionnaire comprising 94 items. We analysed changes in the intake of fruit and vegetables, snacks, fibre, whole grains, vitamin C, saturated fat, unsaturated fat and total energy. We also assessed overall dietary habits using a dietary index developed by the Swedish National Board of Health and Welfare. Results were compared between the intervention and control group, as well as stratified by sex within the study groups. Paired t-tests and analysis of covariance were performed. Results A total of 181 patients were recruited to the DiaCert-study, whereof 146 patients had complete dietary data and were included in the analyses. Women in the intervention group had a higher fruit and vegetable intake (p = 0.008) and a higher dietary index (p = 0.007), at three-months compared to women in the control group. They had increased their daily intake of fruit and vegetables by on average 87.4 g/day (p = 0.04) and improved their dietary index by on average 0.8 points (p = 0.01) from baseline to follow-up. No effect was found in men. Conclusions Women, but not men, receiving a smartphone-based physical activity intervention improved their total intake of fruit and vegetables. The transfer effect, i.e. an intervention aimed at promoting one health behavior that facilitates changes in other health behaviors, may differ between the sexes. Trial registration ClinicalTrials.gov Identifier: NCT03053336; 15/02/2017.

BACKGROUND Despite the large impact that dietary habits have in the management of diabetes, few tools for supporting healthy eating habits are available for persons with diabetes. OBJECTIVE The aim of this randomized clinical trial is to evaluate the effect of a 12-week, mobile health (mHealth), app-based intervention promoting healthy eating habits among patients with type 2 diabetes. METHODS The HAPPY (Healthy eating using APP technologY) trial is a randomized clinical trial with two arms aiming to include 200 patients, 18 years of age or older, with type 2 diabetes. Both women and men are eligible for inclusion. Study participants are randomized 1:1 to an intervention group, where they are instructed to use a smartphone app promoting healthy eating, or to a control group, where they receive standard primary care only, for a period of 12 weeks. Each week a new topic (eg, vegetable intake) is introduced via the app. After an introduction text, the user is given a topic-related activity to perform (eg, eat one additional serving of vegetables per day during that week). The app records daily progress and sends automatic reminders or feedback to the user. Dietary intake, body composition, clinical variables, and biomarkers are measured at baseline and at 3- and 6-month follow-ups. An extensive web-based questionnaire comprising several validated questionnaires assessing a number of lifestyle factors is distributed via email at baseline and at 3-, 6-, and 12-month follow-ups; lifestyle factors include, for example, sleep, physical activity, eating behavior, and health-related quality of life. The effect of the intervention on dietary intake (primary outcome) and on glycated hemoglobin and blood lipid levels, body composition, blood pressure, other lifestyle factors, and overall health (secondary outcomes) will be assessed. RESULTS Data collection is ongoing. Recruitment of participants started in January 2019. Findings from the study are expected to be published by the end of 2021. CONCLUSIONS Technology development provides new ways to promote and support long-term adherence to healthier eating habits. mHealth-based approaches allow for real-time interaction and the delivery of an intervention at any time. Further, focusing on overall diet allows the user to apply new knowledge to current eating patterns, creating an individualized approach. In this study, we evaluate the effect of using a new smartphone app promoting healthy eating habits on dietary intake, clinical markers, and lifestyle factors among patients with type 2 diabetes. CLINICALTRIAL ClinicalTrials.gov NCT03784612; https://clinicaltrials.gov/ct2/show/NCT03784612 INTERNATIONAL REGISTERED REPORT DERR1-10.2196/24422