Table 2.

Summary table of reviewed studies.

Study	Research Design	Sample Characteristics	Themes of the Findings on Family Factors of Adolescent KAP
Author, year, country of origin Aim(s)	Data collection method, setting, source of data, analytical method	Sample size, age and sex of adolescents (other informants indicated in brackets), sampling method
Backett-Milburn, 2006, UK [42] To examine the perceptions and understandings underpinning the dietary practices in families with ‘normal’ weight and ‘overweight’ young teenagers living in poorer socio-economic circumstances	DI Home setting in socio-economically disadvantaged areas in Eastern Scotland Reported by parents/main food providers Inductive thematic analysis	n = (34) Aged 13–14 years Female = (97%) Purposive sampling by gender, BMI, and sociodemographic details	Attitudes: Family motivation (B) Practices: Food preparation and availability (F), Parenting style (F/B)
Backett-Milburn, 2010, UK [43] To understand more about the social and cultural conditions which might be promoting more positive dietary health and physical well-being amongst middle class families	DI School setting in relatively advantaged areas in Eastern Scotland Reported by parents Not specified (Inductive thematic analysis)	n = (35) Aged 13–14 years Female = (94%) Purposive sampling by sociodemographic details	Knowledge: Nutrition Education (F) Attitudes: Cultivation of food preference (F), Family motivation (F) Practices: Food preparation and availability (F), Time and cost (B), Parenting style (F), Parental practical knowledge and attitudes (F)
Banna et al., 2016, Peru [38] To understand socio-cultural influences on eating among adolescents in periurban Lima, Peru using qualitative methods	DI Home setting in low-income Spanish-speaking district Reported by adolescents Direct content analysis	n = 14 Aged 15–17 years Female = 43% Purposeful random sample from census	Knowledge: Nutrition Education (F), Child involvement (F) Attitudes: Family motivation (F) Practices: Food preparation and availability (F), Time and cost (B)
Bassett, 2008, Canada [44] To explore how adolescents and parents negotiate adolescents’ increasing food choice autonomy in European Canadian, Punjabi Canadian, and African Canadian families	DI, participant observation at a family meal and a grocery shopping trip with the family shopper(s) Home setting Reported by related adolescents and parents separately Thematic and constant comparative analyses	n = 47 (62) from 36 families Aged 13–19 years (mean = 41 years) Female = 72% (68%) Snowball sampling	Knowledge: Nutrition Education (F), Family illness experience (F) Attitudes: Family motivation (F) Practices: Food preparation and availability (F), Parenting style (F)
Berge et al., 2012, USA [35] To explore multiple family members’ perceptions of risk and protective factors for healthy eating and physical activity in the home.	Multi-family FG Community setting Reported by adolescents and family members, jointly Grounded hermeneutic approach	n = 70 (33) from 26 families Aged 8–12, 13–18 and ≥19 years (26–61 years) Female = 54% (67%) Voluntary response sampling	Attitudes: Family Health (F, Cultivation of food preference (F, Family Motivation (F) Practices: Food preparation and availability (F), Time and cost (B), Parenting style (F)
Brown et al., 2015, Botswana [45] To describe the factors that influence adolescent and adult perceptions and attitudes related to adolescent diet in Botswana	FG School setting Reported by unrelated adolescents and parents Not specified (low level, non-abstract, direct interpretation)	n = 12 (3) groups Aged 12–18 years Female = 6 groups (not specified) Purposive sampling by SES	Practices: Food preparation and availability (F), Time and cost (B)
Calvert et al., 2020, UK [46] To explore the perceptions of healthy eating behaviours and the influences on eating behaviours amongst 11-to-13-year-old secondary school students	Semi-structured same-sex FG Schools located in deprived areas of England Reported by adolescents Thematic framework analysis	n = 46 Aged 11–13 years Female = 54% Purposive sampling of selected community (low-income)	Attitudes: Family motivation (B) Practices: Food preparation and availability (B), Time and cost (B)
Chan et al., 2009, HK [33] To explore Chinese adolescents’ perceptions of healthy eating, their perceptions of various socializing agents shaping their eating habits, and their opinions about various regulatory measures which might be imposed to encourage healthy eating	FG Low to middle class population Reported by adolescents Comparison analysis method	n = 22 Aged 13–15 years Female = 41% Purposive sampling of selected community	Knowledge: Nutrition Education (F) Practices: Time and cost (F), Parenting style (F)
Christiansen et al., 2013, USA [47] To understand environmental factors influencing the food-related habits of low-income urban African American adolescents	DI, FG sessions, and direct observation Baltimore City Recreation Centers located in low-income predominantly African-American neighborhoods participating in Baltimore Healthy Eating Zones (BHEZ) Reported by adolescents Thematic analysis	n = 20 Aged 10–16 years Female = 75% Stratified, purposive sampling	Knowledge: Nutrition Education (F), Child involvement (F), Family illness experience (F) Attitudes: Family health (F), Family motivation (F/B) Practices: Food preparation and availability (F), Parenting style (F)
Correa et al., 2017, India and Canada [48] To understand perceptions and attitudes of Indian-origin adolescents in India and Canada that may contribute to healthy eating behaviour	FG School setting in rural and urban India, and urban Canada Reported by adolescents Thematic analysis with framework approach	n = 73 Aged 11–18 years Female = 53% Stratified, purposive sampling	Knowledge: Nutrition Education (F) Attitudes: Family motivation (B) Practices: Food preparation and availability (F/B), Time and cost (B), Parenting style (F)
Cullen, 2002, US [49] To assess social-environmental influences on children’s FJV and low-fat choices	FG by ethnicity School setting among low-income families Reported by adolescents and parents separately (relationship not specified) Not specified	n = 180 (40) Aged 9–12 years (mean = 36, 41, 44 years) Female = not specified (91.7–100%) Voluntary participation	Attitudes: Family motivation (F/B) Practices: Food preparation and availability (F/B), Time and cost (F/B), Parenting style (F)
Darling, 2015, US [39] To gain a deeper and more insightful understanding of the family food ecosystem, parental modeling, and parental indulgence, and their potential relationship to adolescent health and well-being	DI School setting Reported by parents Content analysis	n = (29) Grade 10, appx aged 15 years (35–60 years) Female: (86%) Voluntary response sampling	Knowledge: Child involvement (F/B), Family illness experience (B) Attitudes: Family health (F), Family motivation (B) Practices: Food preparation and availability (B), Time and cost (B), Parenting style (B)
Fielding-Singh, 2017, USA [50] To examine an overlooked contributor to family diet: fathers	DI Home setting in middle or upper class families Reported by related adolescents and parents separately Qualitative content analysis	n = 53 (56) from 44 families Aged 12–19 years Female = not specified (75%) Purposive sampling by family characteristics of interest	Attitudes: Family motivation (B) Practices: Food preparation and availability (F), Time and cost (B), Parenting style (F/B), Parental practical knowledge and attitudes (B)
Fielding-Singh and Wang, 2017, USA [51] To explore how mothers and adolescents across SES talk about food	DI Community setting across socioeconomic status Reported by related adolescents and parents separately Qualitative content analysis	n = 62 (62) from 62 families Aged 12–19 years Female = 61.3% (100%) Purposive and theoretical sampling by socioeconomic status	Knowledge: Nutrition Education (F), Child involvement (F/B) Attitudes: Cultivation of food preference (F/B), Family motivation (F/B) Practices: Time and cost (B), Parenting style (B). Parental practical knowledge and attitudes (F)
Fitzgerald et al., 2010, Ireland [52] To explore children’s and adolescents’ perspectives on the potential individual, social, environmental, and developmental factors that influence their food choices.	FG Primary and secondary schools Reported by adolescents Inductive thematic analysis	n = 29 Aged 9–18 years, mean = 13.67 Female = 55% Random sampling	Practices: Food preparation and availability (F), Time and cost (B), Parenting style (F)
Fuster et al., 2019, USA [36] To examine the perceived connections between culture and food practices among Latino pre-adolescents and their parents	DI Community setting Reported by parent-adolescent dyads/triads jointly Not specified (Content analysis)	n = 17 (15) from 15 families Aged 9–12 years (37.4 ± 5.1 years) Female = 47.1% (93%) Purposive sampling by ethnicity and age, and convenience sampling	Practices: Food preparation and availability (F), Time and cost (F/B), Parenting style (B), Parental practical knowledge and attitudes (F)
Garcia et al., 2019, USA [53] To increase understanding of the factors that influence Hispanic/Latino childhood obesity through an intergenerational lens including children, parents/caregivers, and grandparents.	Semi-structured FG Community based organizations in Los Angeles County Reported by adolescents Thematic analysis	n = 22 Aged 10–17 years Female = 52%, one unknown Not specified	Practices: Food preparation and availability (B), Time and cost (B), Parenting style (F/B)
Goh, 2009, US [54] To explore adolescent, parent, and community stakeholder perspectives on barriers to healthy eating and physical activity, and intervention ideas to address adolescent obesity	FG and DI School setting Reported by related adolescents, parents and community members separately Not specified	n = 119 (63) Mean age = 12 years Female = 61% (84%) Not specified	Knowledge: Child involvement (F) Attitudes: Family health (F), Family motivation (B) Practices: Food preparation and availability (B), Time and cost (B), Parental practical knowledge and attitudes (B)
Gray, 2015, Canada [55] To examine the eating behaviours and nutrition knowledge of young women in an Ontario secondary school	DI Private room within school Reported by adolescents Not specified (Thematic analysis)	n = 20 Aged 14–17 years Female = 100% Not specified	Knowledge: Nutrition Education (F/B), Child involvement (F), Family illness experience (F) Attitudes: Family motivation (F) Practices: Food preparation and availability (F), Parenting style (F)
Gunther et al., 2019, USA [56] To identify practices that parents use to influence early adolescents’ food choices during independent eating occasions (iEOs) from parent and child perspectives.	DI Community setting among low income families Reported by related adolescents and parents separately Directed content analysis	n = 44 (49) Aged 10–13 years (26–65 years) Female = 56.8% (89.8%) Purposive sampling by race and ethnicity, and convenience sampling	Knowledge: Nutrition Education (F) Attitudes: Family motivation (F) Practices: Food preparation and availability (F), Parenting style (F)
Hattersley, 2009, Australia [57] To explore adolescents’ and parents’ perceptions, attitudes, and interactions in regards to screen time (ST) and sugary drink (SD) consumption	Semi-structured FG School setting in low to middle SES areas Reported by unrelated adolescents and parents Thematic analysis	n = 31 (32) in 9 FG Aged 13–16 years (mean = 46 years for mothers, 43 years for fathers) Females = 42% (63%) Purposive for low-middle SES	Knowledge: Nutrition Education (F) Attitudes: Family motivation (F) Practices: Food preparation and availability (F), Parenting style (F)
Heidelberger and Smith, 2015, USA [58] To pilot Photovoice methodology with low-income, urban 9- to 13-year-olds to gain insight about their food environment and to determine whether this methodology was engaging and acceptable to them	DI Afterschool programs for youths in Supplemental Nutrition Assistance Program (SNAP)-eligible low income households Reported by adolescents Open coding method	n = 29 Aged 9–13 years, mean = 11 Female = 31% Not specified	Knowledge: Nutrition Education (F) Attitudes: Cultivation of food preference (F) Practices: Food preparation and availability (F), Parental practical knowledge and attitudes (F)
Holsten, 2012, US [59] To explore children’s food choices in the home with particular attention to environmental influences	DI School setting Reported by adolescents Grounded theory and content analysis	n = 47 Aged 11–14 years Female = 51% Maximum variation sampling by race, ethnicity, household income, and BMI	Attitudes: Cultivation of food preference (F), Family motivation (F/B) Practices: Food preparation and availability (F/B), Time and cost (F/B), Parenting style (F/B), Parental practical knowledge and attitudes (F)
Islam et al., 2019, Bangladesh [60] To explore adolescents’ and mothers’ perception of broader sociocultural aspects that sculpt the food choices, eating habits and physical activity behaviours of adolescents in Matlab, Bangladesh	FG Home setting in poor, rural areas Reported by related adolescents and parents separately Inductive thematic analysis	n = 4 (2) groups with 6–8 participants per group Aged 14–17 years Female = 2 groups (2) Purposive sampling	Attitudes: Cultivation of food preference (F) Practices: Food preparation and availability (F), Time and cost (B), Parenting style (F), Parental practical knowledge and attitudes (B)
Kaplan et al., 2006, USA [37] To explore how youth, parents, and grandparents discuss issues related to eating healthfully and unhealthfully and to identify intergenerational strategies for educators to improve this communication.	Semi-structured FG Community setting among low-income populations Reported by adolescents, parents and grandparents jointly Not specified (Content and ethnographic analysis)	n = 21 (23) from 17 families Aged 10–13 years Female = not specified (not specified) Purposive site selection and voluntary response sampling	Knowledge: Child involvement (F) Attitudes: Family health (F), Cultivation of food preference (F), Family motivation (F) Practices: Food preparation and availability (F), Time and cost (B), Parenting style (F/B), Parental practical knowledge and attitudes (B)
Kumar et al., 2016, USA [61] To enable community members to discuss their perceptions of eating habits and physical activity in relation to sixth, seventh, and eighth graders, and reveal facilitators and barriers to healthy eating behaviour and physical activity engagement.	FG Middle school among rural, limited-resources adolescents Reported by related adolescents, parents and teachers separately Not specified	n = 6 groups with 6–8 each (13) 6th grade to 8th grade Female = not specified (not specified) Voluntary response sampling in selected school	Knowledge: Nutrition Education (F) Practices: Food preparation and availability (F), Time and cost (B), Parenting style (F)
Monge-Rojas et al., 2005, Costa Rica [62] To assess the perceptions of rural and urban Costa Rican adolescents about their diet and the factors they consider significant to healthful eating.	FG School setting Reported by adolescents Content analysis	n = 108 Aged 12–18 years Female = unknown, both sex Random sampling	Attitudes: Cultivation of food preference (F) Practices: Food preparation and availability (F), Parental practical knowledge and attitudes (B)
Neumark-Sztainer et al., 2000, USA [63] To (1) increase our knowledge about family meal patterns of adolescents, (2) identify factors that adolescents perceive as reasons for not eating meals with their family, and (3) assess adolescents’ perceptions on whether they eat more healthful foods at family meals than in other eating situations.	FG School setting Reported by adolescents Content analysis	n = 141 Age mean = 12.6 years, 16 years Female = 61% Not specified	Practices: Food preparation and availability (F/B), Time and cost (B), Parenting style (F/B), Parental practical knowledge and attitudes (F/B)
O’dougherty et al., 2006, US [64] To gain insight into parents’ perceptions of the food preferences of their young adolescents, and their negotiating and decision-making strategies around food purchasing and meals	FG School setting among nonwhite and immigrant parents with generally low socioeconomic status Reported by parents Not specified	n = (52) Aged 11–15 years (mean = 37.4 years) Female: (90%) Voluntary response sampling	Attitudes: Cultivation of food preference (F) Practices: Food preparation and availability (F), Time and cost (F/B), Parenting style (F/B)
Ortega-Avila et al., 2019, Mexico [40] To explore adolescents’ perceptions of how the home environment promotes the intake of sugar-sweetened beverages (SSBs) and to identify the potential environmental cues that trigger SSB intake at home	DI Home setting or in public spaces Reported by adolescents Thematic analysis using framework approach	n = 29 Aged 15–19 years Female = 55% Purposive sampling by age and SSB intake	Attitudes: Cultivation of food preference (B), Family motivation (B) Practices: Food preparation and availability (B), Time and cost (B), Parenting style (B), Parental practical knowledge and attitudes (F/B)
Park et al., 2014, South Korea [65] To identify physical and social environments that influence the eating habits of adolescents living in urban South Korea	DI and FG Schools in urban areas Reported by parents and teachers Not specified (Deductive thematic analysis)	n = (9) Aged 10–16 years Female = (not specified) Snowball sampling	Knowledge: Child involvement (F) Attitudes: Cultivation of food preference (F) Practices: Food preparation and availability (F), Time and cost (B)
Pinard et al., 2015, USA [66] To understand influential factors related to family feeding practices among low-income English and Spanish speaking families with school-aged children when eating food away from home (FAFH)	DI Community setting Reported by related parent-adolescent separately Not specified	n = 20 (20) Aged 8–13 years, mean = 10.5 (<21–44 years) Female = 35% (80%) Voluntary response and snowball followed by purposive sampling by dominant language	Knowledge: Nutrition Education (F), Child involvement (F) Attitudes: Family motivation (F) Practices: Food preparation and availability (F), Time and cost (F), Parenting style (F/B)
Povey et al., 2016, UK [67] To explore the beliefs towards eating fruit and vegetables among children aged 9–11 years in a primary school setting	DI School setting in low SE group Reported by adolescents Inductive thematic analysis	n = 11 Aged 9–11 years, mean = 10 Females = 73% Convenience sampling	Knowledge: Nutrition Education (F) Practices: Food preparation and availability (B), Time and cost (F/B), Parenting style (F/B), Parental practical knowledge and attitudes (F)
Power et al., 2010, US [68] To provide insight into the development of a comprehensive program for the prevention of adolescent obesity: the Teen Eating and Activity Mentoring in Schools project	FG School setting from middle-class families Reported by unrelated adolescents, parents and teachers Not specified	n = 16 (6) Aged 12–14 years Female = 69% (67%) Not specified	Attitudes: Family motivation (F/B) Practices: Food preparation and availability (F/B), Time and cost (B), Parenting style (F/B)
Rakhshanderou et al., 2014, Iran [69] To explore the determinants of fruit and vegetable consumption among Tehranian adolescents in 2012	DI School setting Reported by adolescents Qualitative content analysis	n = 31 Aged 11–14 years Female = 48% Convenience sampling	Attitudes: Family health (F), Family motivation (F/B) Practices: Food preparation and availability (F/B), Time and cost (F/B), Parenting style (F/B), Parental practical knowledge and attitudes (F/B)
Rathi et al., 2016, India [70] To investigate adolescents’, parents’, teachers’, and school principals’ perceptions of the main influences on adolescent eating behaviours	DI School setting Reported by related adolescents, parents, teachers and principals separately Thematic analysis	n = 15 (15) Aged 14–15 years Female = 67% (93%) Purposive sampling for participating schools	Knowledge: Nutrition Education (F) Attitudes: Cultivation of food preference (F), Family motivation (F) Practices: Food preparation and availability (F), Time and cost (B), Parenting style (F/B)
Rawlins et al., 2013, UK [71] To explore both individual and family perceptions, intentions and beliefs relating to healthy lifestyles	FG and DI School and community setting Reported by related adolescents and their parents separately Thematic analysis	n = 70 (43) Aged 8–13 years Female = 56% (79%) Purposive sampling by ethnicity and age	Knowledge: Child involvement (F) Attitudes: Family motivation (F) Practices: Food preparation and availability (F), Time and cost (B), Parenting style (F/B), Parental practical knowledge and attitudes (B)
Rodriguez-Perez et al., 2019, Puerto Rico [72] To identify barriers that prevent healthy eating practices in Puerto Rican early adolescents (EAs).	FG Underserved community in both urban and rural settings Reported by related adolescents and parents/caregivers separately Content analysis	n = 52 (17) Aged 12–14 years Female = 67% (76%) Purposive sampling of sites by socioeconomic status	Attitudes: Family motivation (B) Practices: Time and cost (B), Parenting style (B), Parental practical knowledge and attitudes (F/B)
Roth-Yousey, 2012, US [73] To understand parent beverage expectations for early adolescents (EAs) by eating occasion at home and in various settings	FG School and community settings in low-income neighborhoods Reported by parents/ caregivers Not specified	n = (49) Aged 10–13 years Female = (86%) Purposive sampling by BMI	Attitudes: Family motivation (B) Practices: Food preparation and availability (F), Time and cost (F)
Sedibe et al., 2014, South Africa [41] To investigate the narratives pertaining to dietary and physical activity practices by female adolescents in Soweto.	Duo DI School setting Reported by adolescents Thematic analysis	n = 58 Aged 15.3–21.6 years (mean = 18) Female = 100% Voluntary response sampling	Practices: Food preparation and availability (B), Time and cost (B)
Sharif-Ishak et al., 2020, Malaysia [74] To explore the concepts of healthy eating and to identify the barriers and facilitating factors for dietary behaviour change in adolescents.	FG School setting Reported by adolescents Thematic analysis	n = 72 Aged 13–14 years Female = 48.6% Randomly selected schools followed by voluntary response sampling	Knowledge: Nutrition Education (F) Attitudes: Family motivation (B) Practices: Food preparation and availability (F/B), Parenting style (F)
Silva et al., 2015, Brazil [75] To explore how adolescents at a school in the interior of the State of Pernambuco, Brazil, perceive healthy eating	DI School setting in low HDI, agricultural region Reported by adolescents Lexical analysis	n = 40 Aged 10–14 years Female = 62.5% Purposive sampling	Attitudes: Family motivation (F/B) Practices: Food preparation and availability (F), Time and cost (B), Parenting style (F)
Siu et al., 2019, Hong Kong [34] To investigate the barriers to adopting healthy eating habits among secondary school students from low-income families in Hong Kong	FG School setting in a low-income district Reported by adolescents Thematic content analysis	n = 30 Secondary 1 and 4 Female = 50% Purposive sampling by gender, lunchbox practice, and CSSA assistance	Practices: Food preparation and availability (F), Time and cost (B), Parental practical knowledge and attitudes (B)
Snethen et al., 2007, US [76] To understand one Latino community’s perspectives about childhood overweight within this high-risk ethnic group	FG Community setting Reported by unrelated adolescents and parents Thematic analysis	n = 12 (24) Aged 10–12 years Female = 33% (50%) Convenience sampling	Practices: Food preparation and availability (B), Time and cost (B), Parenting style (B)
Steeves et al., 2016, US [77] To provide in-depth information on the social roles that youths’ parents and friends play related to eating and physical activity behaviours and to explore the impact of other social relationships on youths’ eating and physical activity behaviours.	DI Community setting in low-income neighbourhoods Reported by related adolescents and parents separately Direct content analysis	n = 38 (10) Aged 9–15 years Female = 42% (80%) Purposive sampling by genders, ages and neighbourhood locations	Knowledge: Nutrition Education (F) Attitudes: Family motivation (F) Practices: Food preparation and availability (F), Time and cost (B), Parenting style (F), Parental practical knowledge and attitudes (B)
Tiedje et al., 2014, USA [78] To describe the meanings of food, health, and wellbeing through the reported dietary preferences, beliefs, and practices of adults and adolescents from four immigrant and refugee communities in the Midwestern United States.	FG Immigrant and refugee communities Reported by adolescents Content analysis and grounded theory	n = 73 Aged 11–18 years Female = 53% Purposive sampling by age and gender	Attitudes: Family motivation (F/B) Practices: Food preparation and availability (F/B), Time and cost (B), Parenting style (F), Parenting style (B)
Verstraeten et al., 2014, Ecuador [79] To identify factors influencing eating behaviour of Ecuadorian adolescents—from the perspective of parents, school staff, and adolescents—to develop a conceptual framework for adolescents’ eating behaviour.	Semi-structured FG School setting in low- and middle-income countries Reported by unrelated adolescents, parents and school staff Deductive thematic content analysis	n = 80 (32) Aged 11–15 years (mean = 41.2 years) Female = 52.1% (75%) Convenience sampling	Attitudes: Family motivation (B) Practices: Food preparation and availability (F), Time and cost (F/B), Parenting style (B)
Zhang et al., 2018, USA [80] To explore Latino fathers’ perspectives and parenting experiences regarding early adolescents’ eating, physical activity, and screen-time behaviours using the focus group method.	FG Community setting Reported by fathers Grounded theory	n = (26) Aged 10–14 years (33–53 years) Female = (0%) Convenience sampling	Knowledge: Nutrition Education (F), Child involvement (F) Attitudes: Family motivation (F) Practices: Food preparation and availability (F), Time and cost (F/B), Parenting style (F/B), Parental practical knowledge and attitudes (F)

Notes: B = barrier; DI = in-depth interview; F = facilitator; FG = focus group; SES = socioeconomic status.