Abel et al. (2018)29 New Zealand n 20 (10 males/10 females) Varying ethnicity; SES unknown. Interviews (n 20) Facilitators and barriers that influenced the ability to make dietary improvements following a dietary intervention for pre-diabetes. Al-Mohaimeed and Elmannan (2017)30 Saudi Arabia n 37 (19 males/18 females) Saudi ethnicity; mixed education levels. Interviews (n 37) Experiences of overweight or obesity with a particular focus on the perceived barriers and motivators to weight loss. Bombak (2015)31 Canada n 15 (2 males/13 females) Minor ethnic variation (approx. 80% white).

Interviews (n 15)

Follow-up interviews and observation (n 5)

How persons with obesity, with diverse weight trajectories and views on weight loss, described their relationships to food and stigma. Buchanan and Sheffield (2015)32 Australia

n 22 (9 males/13 females)

n 5 (5 health professionals)

Ethnicity and SES unknown.

Focus groups (n 3)

Focus group (n 1)

The phenomena of non-adherence (diet failure) from the perspective of dieters themselves. Clancy et al. (2018)33 USA n 26 (1 male/25 females) 50% Black ethnicity; SES unknown. Focus groups (n 8)

Specific barriers and facilitators participants faced for program engagement and weight loss. How worksites may be able to better engage employees in weight loss programs to improve

their effectiveness.

Coupe et al. (2018)34 UK n 14 (1 male/13 females)a Predominantly White British, 1 Asian woman; predominantly low SES based on postcode. Interviews (n 14) Important factors to consider when tailoring lifestyle interventions for low SES populations. Ekman (2018)35 Sweden n 15 (5 males/10 females) Ethnicity unclear (all born in Sweden apart from one); SES unknown. Interviews (n 15) People's own explanations of weight regain and failure to lose weight permanently. Perception of eating as a way of handling other problems and where weight reduction practices are seen as contributing to weight gain. Eldridge et al. (2015)36 USA n 46 (12 males/34 females) Ethnicity—23 non-Hispanic Black, 20 Hispanic, 3 Other; 23 unemployed, other SES details unknown. Interviews (n 46) Environmental influences on eating behavior change to promote weight loss among Black and Hispanic populations. Hindle and Carpenter (2011)37 UK n 10 (0 males/10 females) Ethnicity and SES unknown. Interviews (n 10)

Experiences of those who have been successful at

weight maintenance.

Jackson et al. (2018)38 UK n 15 (3 males/12 females) 73% White British; SES unknown. Interviews (n 15) Older adults' experiences of and attitudes towards weight management. Karfopolou et al. (2013)39 Greece n 44 (18 males/26 females) Ethnicity and SES unknown. Focus groups (n 8) Lifestyle behaviors associated with weight regulation. Kwasnicka et al. (2019)40 UK n 12 (3 males/9 females) Ethnicity and SES unknown. Interviews (n 12) Theoretical explanations of behavior change maintenance with relation to weight loss maintenance process. Lawlor et al. (2020)41 UK n 26 (11 males/15 females) Predominantly White or White British (76.9%); mixed SES. Interviews (n 26)

Comparison of cognitive and behavioral strategies employed to overcome “lapses” and prevent “relapse” by people who had regained weight

or maintained weight loss after participating in a weight management program.

Mallyon et al. (2010)42 Australia n 14 (8 males/6 females) Predominantly Australian, 1 Pakistani; broadly middle class based on occupation, education and postcode. Interviews (n 26)—two stages of interviews; 2 men were only interviewed once. How men understand and practice dieting within the framework of gendered discourses and gendered relations that can make healthy eating hard to sustain. Mastin et al. (2012)43 USA n 46 (0 males/46 females) African American; low-income. Interviews (n 46) Perspectives on overweight and obesity using social cognitive theory as an interview framework. Metzgar et al. (2015)44 USA n 23 (0 males/23 females) Predominantly White, 2 African American; SES unknown. Focus groups (n 7) Facilitators and barriers to weight loss and weight loss maintenance in women who previously participated in a randomized comparative trial that promoted weight loss using an energy-restricted diet. Natvik et al. (2018)45 Norway n 10 (2 males/8 females) Ethnicity and SES unknown.

Interviews (n 11)

(1 follow-up interview with 1 participant for further detail).

Experiences of people with severe obesity in losing weight and keeping it off for the long term. Nielsen and Holm (2014)46 Denmark n 25 (12 males/13 females) Ethnicity and SES unknown.

Interviews (n 50)

Observation of shopping events (n 12)

Practices and values related to food shopping for individuals who had participated in a dietary intervention. Poltawski et al. (2020)47 UK n 36 (14 males/22 females) 100% White ethnicity; mixed SES.

Interviews (n 103)

34 participants were interviewed 3 times; 34 were interviewed 2 times.

Factors that influence individual experiences and outcomes in a weight management program; why some people did better than others. Reilly et al. (2015)48 Ireland n 4 (male/female ratio for subset unknown)b Ethnicity unknown; mixed SES. Focus group (n 1)b Behaviors, strategies, and attitudes associated with secondary weight maintenance and the psychological and sociocultural factors involved. Rogerson et al. (2016)49 UK n 8 (4 males/4 females) White British; SES unknown. Interviews (n 8) The weight loss experiences of a sample of participants not aligned to clinical intervention research, in order to understand the weight-loss experiences of a naturalistic sample. Romo (2018)50 USA n 40 (19 males/21 females) Predominantly Caucasian/White, 13% Hispanic/Latino; mixed professions, other SES details unknown. Interviews (n 40) The communicative techniques people who have lost weight use to manage interpersonal challenges to weight management. Sand et al. (2017)51 Norway n 12 (0 males/12 females) Ethnicity unknown; students, other SES details unknown. Interviews (n 12) Motivational and environmental factors that support and obstruct weight reduction and weight balance among young adult women. Stuckey et al. (2011)52 USA n 61 (17 males/44 females) Ethnicity and SES unknown. Interviews (n 61) The practices and strategies that help to maintain long-term weight loss in those who have succeeded in maintaining weight loss long term. Yoon et al. (2018)53 South Korea n 73 (28 males/45 females) Ethnicity and SES unknown.

Photo-elicitation group interviews (n 40)

20 groups met 2 times.

The characteristics of the food environment and its influence on weight management. Zinn and Schofield (2012)54 New Zealand n 25 (11 males/14 females) Mixed ethnicities; SES unknown. Focus groups (n 4) Experiences of losing and maintaining weight and proposed ideas for a workplace-based weight loss maintenance intervention.