Table 2 Selected change objectives, theoretical methods and practical strategies

1.1 Acknowledges personal weight changes in past (awareness)

Acknowledges risk of possible future weight gain and its health consequences (risk perception)

Provide feedback using images.

Personalised scenario based risk information

[23].

Familiar physical or verbal images as analogies to a less familiar process.

Plausible scenario with a cause and outcome; imagery. Presented as individual and undeniable.

Weight development over past 5 years is shown in a graph after answering questions about weight history.

Trend for weight development is predicted (e.g. weight gain when no action is undertaken) and compared to the intervention goal: lifelong weight-gain prevention.

1.2 Can explain what the energy balance is, its relation to body weight and small changes in DI and PA (knowledge).

Provide information about behaviour-health link. [11].

Message is relevant and not too discrepant from target's group experience.

Short pieces of factual information about the energy balance, bodyweight, and small changes. Illustrations are added to clarify the text.

1.3 Has stronger positive feelings towards WGP than negative (attitude).

Prompt review of current behavioural goals/perspective

[46]

Anticipated regret [47].

Initiation from the perspective of the learner.

Neutrality of original attitude.

Users fill out advantages and disadvantages of WGP, which results in a decisional balance. They are asked to (re)consider their advantages and disadvantages and relative importance and decide whether they are willing to prevent weight gain. Those who do not yet decide for WGP are asked to consider the long-term consequences of weight-gain prevention and 'no action', and can then re-consider their choice.

1.4 Says to be able to prevent weight gain. (self-efficacy)

Provide general encouragement by modelling

Attention, remembrance, skills, reinforcement; credible source, method and channel.

People are asked if they think they can prevent weight gain. If not, some peers tell their positive experiences with WGP (testimonials).

PO 2. People choose at least one small change in DI or PA.

2.1 Is able to describe personal DI and PA (awareness)

Personal feedback on behaviour [28, 48–51]

Feedback that is individual, follows the desired behaviour closely in time.

They fill out detailed questions on DI and PA. Individual feedback on DI and PA is given, and areas for improvement are indicated. (Oenema, Tan et al. 2005; Oenema, Brug et al. 2008)

2.2 Chooses a change that they feel positive and self-efficacious about (goal commitment + action efficacy).

Prompt intention formation by belief selection [11]

Requires investigation of the current beliefs of the individual before choosing the belief on which to intervene.

The program allows users to choose one change from a personal list. People are asked to pick a change that they think they can change and would enjoy.

2.3 States a clear goal

Guided goal setting [52].

Commitment to the goal; goals that are difficult but available within the individuals practice of coping response.

People set a clear goal, guided by questions in a graphic organiser, such as the size of the change the would like to make./Their answers are presented as their personal goal.

PO 3. People prepare strategies to establish how they will make their chosen behaviour change

3.1 Is able to perform the change (action-efficacy)

Guided action planning [53].

Subskill demonstration, instruction, and enactment with feedback

People answer questions (from a graphic organiser, figure 2) on how they will make the change and which preparation is necessary (such as shopping). This is presented as their action plan.

3.2 Makes the change at the chosen moment (cues to action)

Learn to use cues by implementation intentions (II) [19].

Existing positive intentions and clear cues for action

Guided setting of implementation intentions for initiation of action. They state where when and how the change will be made.

3.3 Receives support from others when necessary (social support)

Mobilise social support

Combines caring, trust, openness, and acceptance with support for behavioural change.

People are motivated for and guided in asking significant others to support their behaviour change. They can talk with other participants on the forum of the intervention website.

PO 4. People change their DI or PA

4.1 Is able to monitor behavioural change and compare it with goal (awareness)

Personal feedback and prompt self-monitoring

Feedback that is individual, follows the desired behaviour closely in time.

People answer questions about their behaviour change over the past week. Next, tailored feedback about performance is given.

4.2 Feels able to pick up change after lapse (maintenance-efficacy)

Reattribution training to prevent relapse [20, 54].

Requires counselling of unstable and external attributions for failure.

People are asked to describe the situation that caused failure. Feedback: concentrate on the success. Learns that a lapse is normal, and that one can learn from it. It is explained to them that the situation caused the failure, but that failure can be prevented by preparing for this situation.

4.3 Identifies high-risk situations (awareness)

Has possible coping strategies available. (self-efficacy?)

Relapse prevention

Planning coping responses

Implementation intentions

[20, 40])

Identification of high-risk situations and practice of coping response.

After describing the failure situation, people receive tailored advice on how to act in this specific situation (cognitive and behavioural). The coping response is formulated as an implementation intention: 'If difficult situation X arises, I'll do Y'

PO 5. People evaluate the success of the behaviour change and its effect on body weight.

5.1 Is able to monitor (changes in) body weight (awareness)

Is aware of normal weight range (awareness of standards)

Monitoring

Guided practice

[55]

Visualisation of personal feedback.

Subskill demonstration, instruction, and enactment with feedback

Familiar physical or verbal images as analogies to a less familiar process.

It is briefly explained why weight monitoring is done and how it should be done. At the same time, guided practice is applied to learn the steps of evaluating body weight in practice. People fill out their bodyweight every week. After four weeks, the program provides them with information about the 'normal range' of their bodyweight, and what it means if they cross this range. Visuals are used to make this visible.

5.2 Attributes weight changes correctly

Shows confidence in WGP (maintenance self-efficacy)

Guided pratice

Reattribution training

Requires counselling of unstable and external attributions for failure.

People passively learn how to recognise and attribute weight gain, and the actions to be taken when weight gain is observed [20].

5.3 Shows commitment to WGP (attitude/commitment)

Behavioural contract

[25]

Should include goal, timeline and rewards, respondent has to agree.

People are asked to sign a personalised 'certificate', which includes tailored information from previous parts of the intervention.

Other components of the website:

Receives support from others when necessary (social support)

Plan social support

Combines caring, trust, openness, and acceptance with support for behavioural change.

The GRIPP website also includes a forum, to stimulate interaction with other participants.

Knows and can cook healthy dishes

Active learning

Time, information and skills

The website includes a database with healthy recipes from all food groups.

Prompt cues

Existing positive intentions and clear cues for action

A selection of useful websites is presented. This includes website on prevention of PA injuries, healthy recipes, etc.

Knows where to find other information about healthy food and exercising