Background: Excess weight is a major risk factor for chronic diseases. In Australia, over 60% of adults are overweight or obese. The overconsumption of energy-dense nutrient-poor (EDNP) foods and low physical activity (PA) levels are key factors contributing to population obesity. New cost-effective approaches to improve population diet and PA behaviors are needed. Objective: This 1-year randomized controlled trial (6-month intervention and 6-month follow-up) aims to investigate whether a tailored intervention using mobile technology can improve diet and PA behaviors leading to weight loss in adults (aged 18-65 years) who are overweight or obese and recruited through a social marketing campaign (LiveLighter). Methods: All eligible participants will provide data on demographics and lifestyle behaviors online at baseline, 6 months, and 12 months. Using two-stage randomization, participants will be allocated into one of three conditions (n=200 per group): tailored feedback delivered via email at seven time points, informed by objective dietary (mobile food record app) and activity (wearable activity monitor) assessment; active control receiving no tailored feedback, but undergoing the same objective assessments as tailored feedback; and online control receiving no tailored feedback or objective assessments. Primary outcome measures at 6 and 12 months are changes in body mass, EDNP food and beverage consumption, and daily moderate-to-vigorous PA (measured via accelerometry). Secondary outcomes include change in fruit and vegetable consumption, daily sedentary behaviors, and cost effectiveness. Results: Enrolment commenced in August 2017. Primary outcomes at 12 months will be available for analysis from September 2019. Conclusions: Tailored email feedback provided to individuals may deliver a cost-effective strategy to overcome existing barriers to improving diet and PA. If found to be successful and cost effective, upscaling this intervention for inclusion in larger-scale interventions is highly feasible. Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN12617000554369; https://www.anzctr.org.au /Trial/Registration/TrialReview.aspx?id=371325&isReview=true International Registered Report Identifier (IRRID): DERR1-10.2196/12782

Image‐based dietary assessment methods have the potential to address respondent burden and improve engagement in the task of recording for dietary interventions. The aim of this study was to assess factors associated with the willingness of adults to take images of food and beverages using a mobile food record (mFR) application. A combined sample of 212 young adults and 73 overweight and obese adults completed a 4‐day mobile food record on two occasions and a follow‐up usability questionnaire. About 74% of participants stated they would record using the mFR for a longer period compared with a written record (29.4 ± 69.3 vs. 16.1 ± 42.6 days respectively; p < 0.0005). Multivariable logistic regression was used to identify those who were more likely to record mFR in the top tertile (≥14 days). After adjusting for age and gender, those with a BMI ≥ 25 were 1.68 times more likely (Odds Ratio 95% Confidence Interval: 1.02–2.77) than those with BMI < 25 to state a willingness to record with the mFR for ≥ 14 days. The greater willingness of overweight and obese individuals to record dietary intake using an mFR needs further examination to determine if this translates to more accurate estimates of energy intake.

Background: Rates of obesity among black African and black Caribbean women in the UK are consistently higher than among white women. Cultural, attitudinal and behavioural differences may contribute to ethnic variation in weight, and the present study aimed to explore attitudes towards weight and weight control among black and white British women using a qualitative approach. Methods: Ethnically homogeneous focus groups were carried out with 25 white women [mean (SD) body mass index (BMI, kg m^–2) = 26 (7.2) kg m^–2] and 24 black women [mean (SD) BMI = 29 (6.6) kg m^–2]. Women were recruited from London boroughs (Lambeth, Southwark and Croydon) and Guildford, Surrey, and focus groups were conducted in London. Focus groups were recorded and transcribed verbatim, and were analysed using thematic analysis. Results: All participants had fairly good knowledge of the causes, consequences and treatment of being overweight. However, black women primarily emphasised the health consequences of being overweight, whereas white women were more likely to focus on the perceived social and emotional consequences. White women associated being overweight with negative character traits, whereas black women had a broadly positive attitude towards larger body sizes. Conclusions: Black women were as well-informed about the causes and health risks of obesity as white women in this sample of mainly educated, working women, although they were more accepting of larger body sizes and experienced less social pressure to be slim.

Assessing the implementation of nutrition interventions is important to identify characteristics and dietary patterns of individuals who benefit most. The aim was to report on young adults’ experiences of receiving dietary feedback text messaging intervention. Diet was captured using an image-based 4-day mobile food record^TM application (mFR^TM) and assessed to formulate two tailored feedback text messages on fruit and vegetables and energy-dense nutrient-poor (EDNP) foods and beverages. At 6-months 143 participants completed a second mFR^TM and a questionnaire evaluating the dietary feedback. Participants who agreed the text messages made them think about how much vegetables they ate were more likely to increase their intake by at least half a serve than those who disagreed [odds ratio (OR) = 4.28, 95% Confidence Interval (CI): 1.76 to 10.39]. Those who agreed the text messages made them think about how much EDNP foods they ate, were twice as likely to decrease their intake by over half a serve (OR = 2.39, 95%CI: 1.12 to 5.25) than those who disagreed. Undertaking detailed dietary assessment ensured the tailored feedback was constructive and relevant. Personal contemplation about vegetable and EDNP food intake appears to be a mediator of dietary change in young adults.

Background: The Tailored Diet and Activity (ToDAy) study aims to build on the campaign by adding a digital intervention with the potential to provide wide-reaching, cost-effective weight management support. Objective: The ToDAy study aims to build a tailored intervention using mobile technology to improve diet and physical activity behaviours in adults with overweight and obesity. The main objectives were to identify behavior change techniques for diet and physical activity (PA) change for weight loss and explore preferences for digital intervention features that would be effective in changing diet and PA behaviors. Methods: This qualitative study uses the principles of a person-based approach to intervention development; the behavioral intervention technology framework; and the capability, opportunity, motivation, and behavior (COM-B) framework. Focus groups and telephone interviews were conducted with 56 adults in Western Australia. Open-ended questions and example intervention features were used to explore the usability and acceptability of the self-monitoring tools, knowledge about effective weight-loss strategies, and acceptability of tailored feedback. Findings from the focus groups and interviews were analyzed using thematic analysis. Results: Qualitative findings revealed an awareness of key public health messages but a lack of confidence in how to perform these behaviors to help manage their weight. A total of 4 major themes were identified and mapped to the domains of the COM-B framework: (1) misinformation, (2) environmental support, (3) social norms, and (4) confidence. Conclusions: This study explores users’ capability, opportunity, and motivation to perform the target behaviors for weight loss. The findings suggested that a digital weight management intervention using a mobile food record and activity trackers to inform tailored feedback may be acceptable and feasible. Participants expressed a preference for simple expert advice, digital self-monitoring tools, and visual feedback. International Registered Report Identifier (IRRID): RR2-10.2196/12782