Table 2 Representative quotes for sub-categories

Category: support

 Professional support

‘And I do believe that we need some, to have a good skill mix and, and multi skilled individuals.’ (S4)

 Characteristics of successful professional’s support

‘Yeah, I think there’s so much judgement around being overweight in the health professional world, you know? ‘Cause not all dietitians' are non-judgemental about overweight children. And when you get a parent who is so defensive and being so full of barriers my judgement of that parent is horrendous. So I think it is a very skilled area to work in because you have got to be non-judgemental at all times, even when you’re told ridiculous things.’ (S8)

 Peer support

‘People realise that they’re not the only ones who are struggling. And you can build friendship groups and create almost a, a cooperative around healthy lifestyle factors.’ (S4)

 Family support

‘If the parent is open and willing to change, then the, then the teenager is. If the parent is defensive and, “You haven’t, your diet hasn’t worked for me,” or, “The GP doesn’t help,” or, “We’re all overweight.” Then the child, the teenager is very unreceptive.’ (S8)

Category: tailoring

 Tailored to age group and individual

But, yeah. It’s, it’s very hard and you do have to take a lot more time and consider the individual as well. 'Cause they are young adults at the end of the day. So it’s not, it’s not as simple as just going and, and picking something up last minute for the store cupboard and going and thinking, “Oh, that’ll be a good incentive.” You’ve got to try and think about the person that you’re working with (S2)

‘I don’t think they particularly think about long term what it’s gonna do to their health. I think that it’s pretty much in the, it’s in the here and now isn’t it …how they feel at that time?’ (S9)

 Delivery mode

‘I think, I think a mixture, because I think you would, you will get some, some young people that, especially if they’ve got, like, they’re really self-conscious, they wouldn’t want to be in a group situation. But then I think you’ve got others that would thrive in a group situation, because, you know, they know it’s not just them that’s, that’s, that’s, you know, maybe got a weight issue, or …I think it’s a little bit of, you know, when you’re with other people you can, you know, you can spur each other on, can’t you? Give each other encouragement and …I, I, I think a mixture.’ (S9)

Category: intervention content

 Easing prior fears

‘You, you could have a promotional site for the program where there might be clips on there of, video clips of what participants have done before and what people have said, participants have said. So, you know, I think people always do want information. Where would they go for information? I would imagine a website.’ (S1)

 Weight loss vs Health

‘I think it doesn’t really matter what the primary motivation is, once you’ve got them there you can sell the message of how losing weight does help to improve their, their, their health. I think adolescents, as well as some adults, are concerned about their appearance, so if their appearance is driving them into your (coughs) excuse me, into their, into your arena, once you’ve got them there, it’s selling the health message.’ (S4)

 Emotional and psychological support

‘I think that just shows that their self-esteem is so fragile that that needs to be the number one priority in the program is to build, build the self-esteem of the teenager.’ (S8)

 Responsibility

‘Well, definitely at, at school, and in terms of what they eat between meals and things, I think they have sole control over it. Over, over the meals themselves the parents are the ones that buy the food. Yeah. So, so I think they, they, it’s going to be shared responsibility between the … it can't be all one, or all the other.’ (S10)

 Physical activity

‘It’s about being free, it’s about easy access, it’s about being able to get there.’ (S5)

 Technology

‘They love apps, anything like that, social media, you’ll, you’ll get them, you’ll grab them.’ (S5)

 Longer term support

‘The groups need to go on for a long time for far more than a year to, to sustain real change I would think.’ (S8)