To identify key stakeholders, as part of the discover phase, a service design workshop [63] was organized with a multidisciplinary team of stakeholders, consisting of end user representatives (ie, people with obesity aiming to maintain weight after initial weight loss; n=2), health care personnel (ie, health care providers; n=5), and project group representatives (n=3). See Figure 2 for study participants, including the participants in the service design workshop.

The stakeholder identification workshop was led by a service designer and aimed to create a map of key stakeholders [63] to involve in the research and design process. On the basis of the methods from stakeholder theory and service design [36,63,73,77,78], idea generation was facilitated during the workshop by using a large whiteboard stakeholder map as a mind mapping tool [63], generating a preliminary list of potential stakeholders. The initial list of stakeholders was then narrowed to key stakeholders based on group discussions and mutual agreement during the workshop session. The broad and multidisciplinary stakeholder involvement in this study is part of a holistic and human-centered development [36,39,70,73].

Prospective end users (ie, people with obesity aiming to maintain weight after initial weight loss—the intervention target group) were defined as adults aged 18 years or above, with BMI ≥30 kg/m² [79] before weight loss, who had recently lost 8% weight or more (eg, through a low-calorie diet or lifestyle change program), and who were in need of support to prevent weight regain. People who met these criteria and had previously experienced weight loss, which was followed by weight regain and/or weight maintenance, were selected for study participation. Eligible participants also had to have access to the internet and be fluent in the Norwegian language. Recruitment was conducted over several weeks by 3 collaborative leading obesity research and treatment centers in Norway through convenience sampling, that is, people meeting the inclusion criteria were invited to participate in the study by their health care provider when undergoing treatment or during outpatient follow-up visits. Potential study participants (ie, prospective end users) received written and oral study information, and were invited to participate in individual interviews and focus groups at local hospitals and research centers (Figure 2). If interested, the potential participants were contacted by the research team, provided with an appointment time, and informed that they would receive a gift certificate (approximate value US $30) as compensation for time spent or of potential costs (eg, transport and parking). Representatives of other key stakeholders identified during the stakeholder analysis (eg, health care providers) were contacted based on convenience sampling and invited to participate in individual interviews and focus groups through the collaborating health care institutions. See Figure 2 for details.

This study was approved by the Hospital Privacy and Security Protection Committee (institutional review board, approval number: 2017/12702) at Oslo University Hospital (OUH) in Norway, one of the largest medical centers in northern Europe. All participants involved in this study received study information and signed a written informed consent form before participation.

As part of the data collection, individual semistructured interviews were performed with prospective end users (n=11) who had recently lost weight and needed support and guidance to prevent weight regain. Other key stakeholders (n=13) were also interviewed to capture a broad perspective and understanding of end user challenges, values, and needs to maintain weight after weight loss [36,73,80] (Figure 2). Interviews with end users and other key stakeholders were guided by the overarching research question: What are the values and needs of people with obesity aiming to maintain weight after initial weight loss?

Individual interviews (60-min to 90-min long) were performed and audio recorded by the first and third author (RA: 17/23, 73%; MS: 6/23, 26%). A semistructured interview guide was developed (Multimedia Appendix 1), providing an overview of the themes to explore. These themes included everyday life, behavior, thoughts, feelings, routines, challenges, strategies, values and needs to maintain weight, experiences and preferences related to health apps, activity and nutrition tracker, and weight management technology (eg, apps, health forums, web-based weight management programs, videos, blogs, and wearables).

To further explore and validate the everyday needs of end users and elaborate on engaging and motivating design elements that could potentially support weight maintenance in eHealth design, 3 focus group sessions were held [80-82]. In 2 focus groups, 10 end users (n=10) participated, 5 in each group. In the third focus group, other key stakeholders (ie, health care personnel) participated (n=6) [81,82] (Figure 2). The focus groups lasted approximately 2.5 hours and were facilitated by a service designer and the first author (RA). A digital designer and a Scrum (ie, Agile project management methodology or framework) product owner also participated in the focus groups. The focus group sessions had an explorative and creative character, applying participatory and ideation methods from design thinking [73]. All 3 focus groups were given the following assignment and topics to discuss.

First, a “What is your favorite app?” assignment was performed, where participants described and/or suggested their own apps. The assignment was performed to stimulate creativity and to create trust and social connections within the group. During the assignment, positive and negative aspects of the apps were elaborated on employing brainstorming techniques. The following topics were then explored to provide input for the main research questions:

Sticky notes and a large whiteboard were used to discuss these topics (ie, open-ended questions) with the focus group participants, eliciting potential unmet user needs. This technique was used to create an image of the diversity of user needs [73]. A dynamic and informal discussion, where focus group participants could instantly react to each other’s suggestions, provided the researchers with a broad impression of the topics [81].

To identify engaging and motivating design elements, feature cards were applied based on design methods and principles from open card sorting (although applied in a less traditional way than card sorting tasks for information architecture; Multimedia Appendix 2) [83-87]. The cards contained PSD principles and BCTs identified in the previously mentioned scoping review [23]. Additional design elements were included to explore other potentially engaging elements supporting behavior change and to facilitate the creative process related to users’ requirements, preferences, and ideas to meet their needs [23,86-90]. These elements include metaphors (eg, when a target is reached, a flower grows in a garden), avatars (eg, a virtual or digital person based on oneself), and gamification elements (eg, points and trophies).

The participants could also choose to develop their own cards with motivational elements through sketching or writing, as some cards had no content (ie, were blank). Examples of how the design elements could be used in app design were presented during the introduction. The focus group participants could choose and sort the cards they identified as useful (ie, to motivate and support weight maintenance) and then share their results in an open group discussion. Participants sorted the selected cards into groups of must have, nice to have, and not needed.

As part of the define phase, verbatim transcription of audio recordings of the anonymized interviews (n=23) were analyzed by the first author (RA). Thematic analysis was applied, inspired by Brown and Clark [92], using NVivo (QSR International) qualitative analysis software. End user needs were identified through in-depth analysis and inductive coding of the data until saturation was reached [92]. A second researcher (MS) analyzed 17% (4/23) of the transcribed interviews for analysis validation. Overall, 2 researchers (RA and MS) participated in all of the coding of the identified needs into value categories (performed independently of each other), and a third researcher (JW) participated in validating 1/3 of the coding. The findings were continuously discussed within the research team during this process (RA, LN, MS, JW, LP, and JH). All steps contributed to the development of a comprehensive understanding of the data and to identify a representative and specific set of end user values and needs, as expressed by the key stakeholders [75,76,93]. Multimedia Appendix 3 presents examples from the analysis process related to the key values.

The design elements and related needs identified during the 3 focus group sessions were analyzed, documented, and combined by the first author into one overview in a mind mapping tool (XMind, XMind Ltd) [94]. The findings were discussed with the service designer, digital designer, and the Scrum product owner participating in the focus groups, next to the research team. The identified design elements served as input for the analysis and identification of PSD principles and BCTs to meet end user values and needs (Figure 3).

To identify PSD principles and BCTs, the PSD model by Oinas-Kukkonen [26], behavior change taxonomy by Michie [43], previously conducted scoping review [23], and design elements from the focus group sessions were employed (Figure 3). Through small iterations in the analysis process, needs could be linked to one or more end user values. These could then be linked to possible PSD principles and BCT clusters, leading to the formulation of high-level requirements and suggested design features. The identification analysis was performed by the first author and one of the coauthors (RA and MS). A third coauthor (JW) validated 1/3 of the analysis with regard to inconsistencies and disagreements (randomly selected) and contributed to the requirement development. Data analysis and requirement development were continuously discussed by the research team. This identification process resulted in an overview of PSD principles and BCTs aimed at supporting end user values and needs as well as high-level requirements of an eHealth intervention aiming to support weight loss maintenance. The high-level requirements will allow for innovation during the next steps of the design and development process (Figure 1).

The key stakeholders identified were prospective end users (ie, people with obesity aiming to maintain weight after initial weight loss) and health care providers from primary and secondary health care providing health services to the target group. Additional key stakeholders identified were policy makers (ie, from the Norwegian Directorate of eHealth); representatives from a patient organization (ie, the Norwegian Association for People with Obesity); and researchers conducting research in behavioral medicine, obesity, and weight loss maintenance with clinical experience. See Figure 4 for a final key stakeholder map. In addition, the multidisciplinary design, software, and content development teams involved in the research project were consulted for expert opinions related to digital design and development (included as indirect stakeholders). Figure 2 presents an overview of key stakeholder involvement in each of the separate research processes in this study (N=50).

A total of 21 prospective end users, 67% (21/50) women, median age 53 years (range 24-70 years), participated in individual interviews and focus groups. As presented in Multimedia Appendix 4, approximately two-thirds of the participating end users reported having had obesity and weight maintenance challenges for most of their life. All end user participants reported having tried various diets (eg, low-calorie and/or very low–calorie diet) and/or conservative treatments (eg, lifestyle programs) to lose weight. They all also described having had several attempts to maintain their weight loss. All participants reported owning a smartphone, tablet, and/or computer and using them on a daily basis for various purposes (eg, social media, news, weather forecasts, financial services, and buying public transport tickets).

Self-management or self-regulation was one of the key values highlighted by participants as important to enable sustainable weight maintenance. Many people who struggle to prevent weight regain have difficulties regulating their eating behavior, engaging in physical activities, and establishing new habits:

In particular, self-regulation strategies and skills to implement into daily routines (eg, planning), dealing with challenges (eg, tempting situations and back on track when weight increases), and strategies for coping with emotional eating and impulse control were highlighted as essential needs within the concept of self-management:

For self-management, comprehension of one’s own process to create awareness and reflection around one’s own behavior was considered an essential need by end users and other key stakeholders:

During the self-management process, the experiences of accomplishment, mastery, and success were deemed especially important to be able to “keep up” over time:

All stakeholders expressed the need for reliable and easily accessible information. As stated by one of the end users, “a lot of information is available for weight loss, but not for weight maintenance.”

All stakeholders emphasized that needs and requirements differ depending on the person and whether the focus is on weight loss or weight gain prevention. The differences described included aspects such as knowledge, support, and differences in self-management strategies to regulate eating behaviors, negative thoughts, and/or emotions:

Tailored support to reach goals and establish healthy habits, including small personal steps (ie, subgoals), and to get personal feedback and “information that fits me” (end user) were other needs expressed within the personalized care value:

Finding motivation to keep up with the new habits was highlighted by all stakeholders as an important factor to keep focus and maintain weight. End users stated that being able to identify individual motivators or reasons (ie, intrinsic motivation) for maintaining weight and being able to select goals related to individual purpose were essential for staying motivated over time. Other key stakeholders described being able to focus on important purposes, defined by the end users themselves, could contribute to “strengthening of self-regulation capacity and the autonomous motivation required” for the necessary processes of change:

Examples of personal motivators described by end users included having good health, being more social, being able to play with grandchildren, being able to work, fit into normal clothes, and feeling confident. Receiving tailored (social) support and confirmation were also described by end users as crucial to stay motivated during difficult times or when struggling to self-regulate. Other key stakeholders described aspects such as practicing new habits and realistic goal setting, instant reinforcements (ie, rewards, tailored feedback) related to goals and outcomes, reminders of past success, and information about positive versus negative aspects of weight maintenance or regain as being of essence for continued motivation.

Feeling supported, with positive feedback to keep focus and stay motivated to maintain weight, was seen as crucial by all stakeholders. Several end users mentioned that they lacked support in their social surroundings and/or avoided social settings as much as possible. They described that being able to receive confirmation and (social) support, the feeling of not being alone, and having support on good and bad days or in crisis situations were important needs to be met during weight maintenance:

Other important aspects mentioned by end users included positive reinforcement (eg, praise and self-selected rewards), just-in-time support (eg, tailored feedback and 24/7 availability), and the ability to learn from others by sharing experiences with people in similar situations (eg, social learning, social comparison, cooperation, and social facilitation). These statements were supported by other key stakeholders:

To feel confident and believe in oneself was mentioned by most stakeholders as being of essence for weight loss maintenance. The participating end users also stated that the focus should be on the whole person, not solely on their weight:

Several end users and other key stakeholders described that many have low self-confidence after several attempts at weight reduction:

Positive focus on one’s strengths and capabilities, the experiences of success, respect for oneself, identity, and self-worth were other areas identified by all end users as important to address to create a more positive self-image and support self-actualization:

Several end users described that the cost of maintaining weight after weight loss tends to outweigh the benefits. End users, therefore, stated that they not only want to focus solely on weight but also on positive health effects of a healthier lifestyle and of being less heavy. They indicated that having a good health was one of their main initial motivators to lose weight. Other key stakeholders highlighted aspects such as focusing on short- and long-term health effects of target behavior as important factors to support a feeling of enhanced control and improved health and well-being:

The end users expressed a preference to bring attention to enjoyable, fun, and positive benefits of healthy behaviors:

To make physical activities more fun, several end users reported using activity trackers or smartphones to monitor activity levels.

In terms of technology, special attention was also directed toward fun and enjoyable elements to stimulate happiness and positive feelings, so that a healthy lifestyle could be followed to maintain weight:

The stakeholders also described being able to focus on short- and long-term health rewards of daily habits, through monitoring and rewarding healthy behaviors or targets, as ways to increase pleasure and happiness. One health care personnel said, “A technology that gives joy and a sense of meaning or added value will be used.”

Suggestions and information to make healthy eating more attractive and tastier were also described as ways to increase pleasure and happiness. Other key stakeholders also described factors such as making healthy eating more attractive and enjoyable, being able to get information on the health benefits of being active, and to see body composition improve as important factors for gaining insight.

Many end users described the freedom to choose and be in charge as essential aspects to independently master their own behavior change process. They stated that mastery could be reached by having knowledge, abilities, and skills to achieve a healthy lifestyle and continue to do so. The end users also expressed that having customized plans (eg, for weekdays, weekends, holidays) would help induce a feeling of free choice, mastery, and control. Other key stakeholders also supported this:

All stakeholders described the following factors as important to be able to choose and continue with healthy habits: facilitating a better understanding of the end users’ own process and behavior, enhancing the understanding of how the body and mind work, and learning about health and strategies for self-regulation:

Focus group findings provided an overview of potential design elements that could meet end user needs when aiming to maintain weight after weight loss. See Table 1 for details. The findings indicate that some design elements were considered more important to incorporate in eHealth weight loss maintenance interventions than others. However, most design elements were characterized as must have during focus groups 2 and 3.

Needs identified during open brainstorming in the focus groups were linked to the design elements. See Table 2 for details. In the analysis process examining the results, the 8 key values were linked to the needs identified.

The findings indicate that several design elements, supported by PSD principles and BCTs, can be applied to facilitate and motivate short- and long-term behavior changes. Positive feedback, associations (eg, prompts and cues), and rewards (eg, earning points and receive trophies) were identified as motivational elements to inculcate new behavior and for short-term goal setting during the focus group sessions. For long-term behavior change, rewarding strategies linked to, for example, self-selected rewards, identity (eg, reminders of past successes), natural consequences (eg, information about health consequences of performing the behavior), and social support (eg, social cooperation and social learning) were elements identified as potential motivators for sustainable change.

The findings presented in Tables 2 and 3, supported by findings from the previously mentioned scoping review [23], served as input in the analysis to identify PSD principles, BCTs, and requirements of an eHealth intervention to support end user values and needs.

The findings from the semistructured interviews and focus groups with key stakeholders were consistent and complemented each other with respect to the 8 interconnected key values that were identified in this study: self-management, personalized care, motivation, feel supported, positive self-image, health, happiness, and autonomy. The key values (ie, main drivers of behavior or high-level requirements) were each supported by identified needs (ie, demands or low-level requirements), sometimes supporting multiple key values. The identified values were interconnected, rather than strictly separated, and dynamic, as the drivers and individual needs can change during long-term maintenance of lost weight.

The 8 identified key values may drive the need for behavior change that is required to successfully maintain weight over time, and motivation and chance for success may increase as these values are met. This means that in eHealth interventions aiming to facilitate sustainable weight loss maintenance, supporting the identified key values in this study could be of essence.

Several of the overlapping end user values identified in this study are in line with research and theories arguing that most behavior is multi-motivated and that a value-driven and positive approach to health and well-being is required to achieve sustainable behavior change [95-98]. In such a holistic approach, behavior tends not to be determined by one value or specific goal but by several dynamic needs simultaneously [96,97,99,100]. Theories about motivation, self-regulation, and social learning [101-104] are likely to be of use in the design of eHealth interventions emphasizing values and needs, as identified in this study. For example, the self-determination theory [103,105] offers a macro theory of human motivation and personality, suggesting that motivation to change is dependent on whether people’s needs for competence, autonomy, and social relations or relatedness are met. A such, self-determination theory could potentially act as a framework to support several of the identified values and needs, including the individual needs for knowledge and skills (ie, competence) to self-manage, and individual differences with regard to personality, psychological, and/or motivational profile [103,105-108].

Several PSD principles and BCT clusters were identified as potentially promising to meet the identified key end user values. Findings from this study are consistent with the results from the scoping review previously conducted by the research team [23], indicating that goals and planning, feedback and monitoring, and social support should be pursued long term to maintain weight [22,23,107,109-114]. However, this study revealed some BCT clusters not previously identified (eg, identity and self-belief) [23] that could be important to maintain long-term weight loss.

The challenge related to weight loss maintenance for people with obesity is evident, as many people struggle to maintain weight and may easily fall back into old habits following weight loss [6]. This can be explained by the nature of habits, as habits are often learned, automatic, and sometimes even unconscious processes formed through repetition [25]. In this study, BCTs within the repetition and substitution clusters (eg, habit formation and habit reversal) were identified. Habit formation can be integrated into eHealth interventions to support the formation of new and lasting habits and might be a missing link in the effort to address the challenges related to weight loss maintenance [7,10,14,15,22,115-121]. To adapt to the dynamic changes in individual needs over time and to support contextual changes, personalization and tailoring were identified PSD principles of essence in this study.

Findings from this study point to a combination of several PSD principles and BCTs as a necessity to meet end user values and needs in eHealth weight loss maintenance interventions. Persuasive technologies and application of PSD principles in digital behavioral interventions might be key to support long-term weight loss maintenance, especially when combined with BCTs and behavior change theories [23,47]. However, evidence and guidance on how to combine these strategies are nonexistent [23]. PSD principles can be applied to create engaging, user-friendly, persuasive technologies that can support healthy choices and decisions and may be particularly important in the adoption of new habits (eg, suggestions, reduction, self-monitoring, rewards, and feedback). On the other hand, BCTs seem to be important for sustainable behavior change, and the identified techniques (eg, goals and planning, monitoring and feedback, repetition and substitution, associations, antecedents, regulation of emotions, self-belief, and identity) can be learned and put into daily life, even without technology.

In this study, for some of the key values, only a few supporting BCT clusters and/or PSD principles could be identified. This could indicate that some BCTs or PSD principles have yet to be discovered, possibly because some needs may be future or latent needs. It could also indicate that BCT clusters (eg, covert learning) [43] that are not fully desired through identified end user values or needs, but could none the less be important for the required behavior change, should receive particular attention in technology design and may need to be combined with PSD principles (eg, rehearsal) [26] to support the user and create the aspired impact on behavior change.

There are numerous potential advantages of digital health technology. Digital technologies can, for example, overcome time and place barriers, with improved accessibility (24/7 availability) and timely support; enable people to track and aggregate real-time data from sensors and smart devices; and may also support personalized and tailored interventions, depending on user behaviors and needs [122]. To date, however, research examining the design for sustainable behavior change is still sparse [23,123].

If centered around end user needs and priorities, digital self-management support systems have the potential to meet several of the key values identified in this study [104,124-128], which might lead to the long-term behavior change needed to maintain weight. The success of such systems also depends on the incorporation of facilitating factors linked to weight maintenance, including self-regulation strategies (eg, cognitive and emotion regulation, goal setting, effective coping, and problem-solving skills), and increased confidence in own ability to self-regulate [13,104,126-128].

Reversal of established behaviors and habits can be challenging, particularly over time [129,130]. However, applying a combination of the identified BCTs and PSD principles (eg, repetition and substitution, identity, feedback and monitoring, goals and planning, and personalization) in future eHealth interventions, linking healthy habits to self-determined goals and identity (eg, individual purpose, health or life goal), might contribute to sustainable behavior change and long-term weight control [52,105,108,125,129,131-136]. According to end users and other key stakeholders, many experience that it costs more than it benefits to change behaviors for continued weight control after weight loss. As identified in this study, digital technologies that are designed to support personal and autonomous motivation, self-efficacy, self-regulation skills, positive body image, self-selected rewards, and health and well-being (eg, not only weight) could also contribute to long-term weight control and improve the cost-benefit ratio that many people experience while trying to balance behaviors to prevent weight regain [23,103,104,111,125,131,134,137,138].

Although eHealth technologies can contribute to improve health care, support sustainable behaviors promoting health and well-being [139], and increase impact and uptake through personalized and tailored design [36,45,122,140-142], eHealth interventions can only be effective if actually used. This means that persuasive and engaging technologies, as examined in this study, have the potential to support people in engagement and adherence to healthy lifestyles in pursuit of their goal of weight maintenance [30,34].

Behavior change interventions are usually complex, and some studies show how interventions incorporating multiple BCTs, rather than just a few BCTs, tend to have larger effects promoting health behavior change [43,54,143-145]. Digital behavioral obesity interventions that combine PSD principles with behavior change theories have also been shown to produce statistically significant weight loss results more frequently [47]. Specifying one ideal combination of PSD principles and BCTs to support sustainable behavior change and weight control in eHealth interventions might not be possible. Varying individual values and needs, which requires a personalized and tailored approach, make specifying an ideal combination at the very least challenging [15,142,146,147]. Investigating which PSD principles, BCTs, and content that is most effective for sustained engagement, for whom and in which context, should be a goal for future research developing or examining digital weight loss maintenance interventions [107].

With several biological, behavioral, psychological, social, and environmental factors interacting, the challenges related to obesity and weight loss maintenance are complex and numerous [16,21]. In this study as well as in the scoping review previously published by the research team [23], personalization and tailoring, including tailored support and personal feedback, were highlighted as factors of great importance for the success of digital interventions targeting behavior change and weight loss maintenance. Individual differences, including personality and psychological profiles that may impact behavior and behavior change, should also be examined and taken into consideration when designing and tailoring such digital interventions in the future [106]. Tailoring based on individual characteristics (eg, personality, motivational orientation) could be of essence when aiming to create effective technological features supporting behavior change [142]. Cognition, affect, and behavior related to individual context have also been identified as core components of engagement and should be considered in the design and development, including the form of delivery and content, of digital interventions aiming to enhance and sustain engagement and support health behavior change [107,147]. In the development process, this issue could be addressed by identifying a variety of user types (eg, personas) [148], and the combination of applied PSD principles and BCTs may potentially be adjusted or tailored per user type [142,149]. Ideally, BCTs and PSD principles applied in eHealth behavior change interventions should allow for flexible interaction and adaptability based on the dynamic and changing individual end user needs over time.

Rapid technology developments have changed the way modern organizations approach innovation to create value for end users and stakeholders [68,69,91,150-152]. This study integrates design thinking with BCTs and PSD principles and can guide co-design processes to identify design elements to meet end user values and needs for behavior change in future interventions [64,65,153]. The proposed method used in this study also unlocks and explores current, latent, and future user needs and possible solutions through its iterative and participatory process [21,39,40,68-72,77,154]. The key values, BCTs, and PSD principles identified in this study can provide input to future design and development processes of eHealth weight maintenance interventions. Co-design and prioritization of BCTs and PSD principles with key stakeholders, including designers and developers, may further develop and specify eHealth interventions, allowing for functional requirements and physical design to be adapted and optimized during prototype development and user testing [40,73,91,155]. In addition, multidisciplinary design teams and quick experiments during the entire design and development process may increase the chance for the technology design to successfully meet user needs. However, as shown in this study, some values and needs could be conflicting. The findings from this study also suggest that some needs, PSD principles, or BCTs for sustainable behavior change are yet to be discovered [23,36].