Table 2 Illustrative Participant Quotations for Theme 1: Therapy Engagement and Progress

1.1 Weighing experience

BW

“There is a lot less anxiety around [being weighed] ... I just kind of get it over and done with. Because I’m not, dreading it really, since I’m not seeing it. I don’t love it, but I’m not dreading it the same way I was.” (Reduced anxiety, BW109)

“I feel a bit anxious for a bit, but then I’m like, ‘whatever’, and just go do something.” (Reduced anxiety, OW112)

“[BW] was quick and painless, you just kind of get up, get weighed go back to bed” (Reduced anxiety, R315)

OW

“I’m more stressed before weighing days, and then the day I’m being weighed, thinking about it more probably … I get anxious, tossing and turning, I think about it, I catastrophise like ‘oh my god it’s gone up 10 kg it’s probably gone up this much, it’s gonna [sic] be this weight. If it’s up this high I’ll do such and such, if it’s below this I’ll do such and such.” (Increased anxiety, OW211)

“Yeah I think that weighing days were definitely the worst ones … you’d wake up and you’d know that you have to be weighed and it was, you know when you get that pit in your stomach where you kind of want to throw up, it was like that.” (Increased anxiety, R315)

1.2 Therapy engagement

BW

“I think sometimes [BW] can exaggerate or catastrophise what your thoughts are because you don’t have any evidence, like you can eat something you are scared of and think ‘Oh my god it’s going to make me gain 5 kg’ and then you don’t really have any way of proving it wrong? Which I think can be hard. But obviously, I know like if I said that, my treatment team would happily provide me evidence that it didn’t make me gain a ridiculous amount of weight. But I think that can be hard.” (Distorted cognitions about weight gain, BW113)

“Not knowing [my weight helps me comply with my meal plan], because then I’m not kind of obsessed about a number all the time and I’m just doing what I have to do really.” (Increased meal plan compliance, BW102)

“I was like well I don’t know my weight. Yes it’s terrifying but at the same time it meant that I focused on getting through my meal and focused on my psychology sessions and the group therapy that we did instead of ‘oh my weight was this today’ … I guess it was just one less thing that I had to deal with.” (Increased therapy engagement, R315)

“The more you check something the more it might be on your mind and by not checking my weight it was something that became less and less pronounced in my day to day [routine].” (Reduced weight preoccupation, R310)

OW

“The longer I get into the admission and the more weight I gain, I get more preoccupied with it [my weight] and I get more anxious. (Increased weight preoccupation, OW212)

“Obviously if it’s gone up more than I’m comfortable with I’m less likely to comply [with my meal plan]. The other week I only drank supplements for the whole day, and refused to get out of the bed other than for meals because of the number jumping up” (Increased resistance to meal plan, OW211)

“Being open weighed definitely impacted on my motivation and ability to stick to meal plan. It made me work “against” therapy and made it harder to comply.” (Increased resistance to meal plan and reduced motivation, R311)

1.3. Progress

BW

“Initially, it was worse...not knowing, predicting the worst, I guess. But then after a couple of weeks, you kind of got used to it and now it’s a bit more peaceful.” (Early adjustment difficulties, OW213)

“[BW] keeps your mind on track of the end result which is getting better. It doesn’t leave you with all these preoccupations and distractions.” (Reduced preoccupation, OW110)

“[BW] was in many ways the only way that I had to learn to not put all the emphasis into my own weight. That, by not knowing my weight, I had to learn to be comfortable not knowing it, and therefore not emphasizing it.” (Reduced weight importance, R306)

OW

“If it [my weight] goes up I tend to get very anxious and tend not to want to do the right things in my treatment, and I want to go home.” (Treatment resistance, OW212)

“I think like weighing for me was the thing that probably kept me back the most when I decided to recover.” (Barrier to recovery, R315)

“I think it’s important for us to see the weight go up because it’s what’s needed, and it will help rationalise those thoughts that if you eat something, you’re not going to magically gain 10 kg, like most of us think.” (Challenging of distorted weight beliefs, OW209)