Health and nutrition beliefs and perceptions of Brisbane adolescents.

Abstract

Objective: To examine the health and nutrition beliefs and perceptions of Brisbane adolescents.

Design and methods: Adolescents completed individual, semi-structured, face-to-face qualitative interviews that were transcribed verbatim and analysed by thematic analysis.

Subjects: Twenty-nine boys and girls aged 13-15 years.

Setting: All adolescents were residents of Brisbane city; interviews were conducted in their homes.

Main outcome measures: Themes raised and the frequency of their occurrence in discussions about health and nutrition.

Results: Health was perceived as being able to carry out daily physical tasks and was also seen as being a direct consequence of undertaking various 'healthy' behaviours (such as eating a good diet, undertaking physical activity and obtaining adequate sleep). Adolescents saw health as being an individual's responsibility (rather than a consequence of factors external to the individual). They identified a healthy diet as eating plenty of fruits and vegetables, being low in fat and balanced. Major barriers identified to healthy eating were taste and convenience.

Conclusions: Adolescents are knowledgeable about behavioural risk factors that influence their health, consider their health as important and are well informed of the characteristics of a healthy diet. They regard health as their own responsibility. Therefore, health and nutrition promotion initiatives may be most effective if they attempt to improve adolescents' perceptions of healthy eating in terms of taste and convenience, rather than just focusing on the provision of information.

Key words: adolescents, Australia, beliefs, health, nutrition, perceptions

(Nutr Diet 2005;62:69-75)

Introduction

Chronic conditions such as cardiovascular diseases, cancer and type 2 diabetes are major causes of mortality in Australia. (1,2) Dietary intakes are thought to be significant contributors to these diseases (3) and adolescence has been identified as an important period for the uptake of dietary and other health behaviours that may continue throughout life.(4) Currently, Australian adolescents have intakes of total fat, saturated fat, fruits and vegetables that are not in accordance with recommendations for chronic disease prevention. (5,6) Therefore, targeting their food and nutrient intakes may be an effective means of decreasing morbidity and mortality from major chronic diseases.

Young children are largely dependent on health-related decisions made at school and by their parents; however, by adolescence they are beginning to accept responsibility for their own health behaviours and attitudes. (7) Much of our knowledge pertaining to health and nutrition-related beliefs, attitudes and perceptions has been obtained from studies among adults, and it is uncertain whether the findings of these studies can be applied to adolescents. (8) Successful strategies to encourage the adoption or maintenance of healthy behaviours in young people depend on understanding the behavioural and psychosocial characteristics influencing their lifestyle choices. (7,8)

For healthy behaviours to be encouraged among adolescents, it is important to identify how adolescents think about health themselves, their perceptions of what influences their health and the importance they place on it. The present study explores these issues and further examines adolescents' understandings of what constitutes a healthy diet and factors that they perceive as hindering them from healthy eating. Qualitative investigation of attitudes about health and healthy eating among adolescents is lacking, particularly in Australia. These findings would be beneficial for designing health- and nutrition-promotion programs that are appropriately targeted, as well as providing useful data for the development of further research examining the relationship between health and nutrition-related beliefs, attitudes, perceptions and dietary intakes among adolescents.

Method

Ethical clearance for the research was obtained from the Human Research Ethics Committee of Queensland University of Technology (Reference number 2095H).

Sample

Adolescents were recruited from the Brisbane Food Study (BFS), a representative population-based study of food-purchasing behaviour conducted in Brisbane City, Australia, in 2000. Further details about the sampling procedure for the BFS are described elsewhere. (9) All households participating in the BFS (n = 1003) were asked whether there were any resident adolescent children between the ages of 13 and 15 years. A total of 89 such households were identified. Parents were provided with information about the adolescent study and asked if their child/children would be willing to participate. If agreeable, parents signed a consent form on their child's behalf (n = 37, 44%), and the family's contact details were released to the principal investigator (KG).

The age range of 13-15 years was chosen on logistic and theoretical grounds. First, there was a sufficient number in this age group who volunteered to participate, and there was a relatively even distribution of males and females. Additionally, all of these adolescents lived at home on a full-time basis (so that influences from their parents could be examined), and were a relatively easy group to organise for interviews. Since adolescence is characterised by change, it was also necessary to focus on a more homogeneous group (in terms of age) for this qualitative study rather than considering a broader age range.

Only one adolescent per household was chosen, to decrease similarities in responses due to shared experiences and upbringing; therefore, 14 adolescents were excluded from the sampling frame (adolescents in households with two or more adolescents between 13 and 15 years of age). In households with multiple eligible adolescents, the oldest adolescent was selected. Eight households did not agree to take part or could not be contacted, resulting in a final total of 29 participants (35% of households with adolescents aged 13-15 years in the BFS, and 78% of those who initially agreed to participate).

Data collection

Data were collected using individual, face-to-face interviews. The interviews had a semi-structured format that focused on addressing a variety of research questions. On average, interviews were an hour in length. At the beginning of the interview, participants were given an interview guide, similar to a questionnaire, to assist in focusing the discussion. They were asked to complete the guide, and then discuss their responses in detail. The interviewer used probes and asked more specific questions that explored their responses in greater depth. The questions used to elicit data, and some examples of the probes used are shown in Table 1.

To open the discussion and identify the relative salience of health, a list of items that may have been important in their lives was presented to the adolescents. This list included school, sports and hobbies, money, family and friends and health. The adolescents were asked to rate each of these factors as important, not important or 'in-between', and were subsequently asked to talk about why each was given the assigned rating. When discussing health, the interviewer asked, 'Can you talk a bit about why your health is important/not important to you at the moment?' In order to elicit their definitions of health, the participants were asked, 'What does health mean to you?' and 'What factors do you think influence your health?'

Adolescents were asked, 'If you had to describe healthy eating, how would you describe it?' Further questions included: 'What do you think stops some teenagers from eating healthy foods at school?' and 'What do you think stops some teenagers from eating healthy foods at home?' Each participant was given a gratuity of $10 ($AUS) to offset any inconvenience incurred as a result of participating in the present study. Interviews were tape-recorded and transcribed verbatim.

Analyses

To determine whether there were any differences between participants and non-participants, the socio-demographic characteristics of participants in the BFS and those who volunteered for the current survey were compared using [chi square]-tests. These tests were two-tailed and results were considered statistically significant at P [less than or equal to] 0.05. Analyses were conducted using SPSS version 10.1. (10)

Data relating to the research questions were indexed and catalogued using NUD*IST. (11) To decrease bias, the coder (KG) was unaware of the gender and socio-economic position of participants while coding. The transcripts were analysed using thematic analysis. Each theme identified in the adolescents' responses was given a label and definition. These were compiled in a coding-book to guide the coding of subsequent transcripts. A summary table of the frequencies of adolescents who raised each theme was produced. Only themes raised by two or more participants were included in the results. Words, phrases and quotes thought to capture the themes were selected and are set with smaller font size in the results.

A reliability analysis was conducted with two additional coders who worked independently. Each coder was given the coding-book and asked to code the raw data, and their results were checked for consistency against that of the principal investigator (KG) and each other. Inter-rater reliability was calculated using the formula: %Agreement = Agreements/(Agreements + Disagreements). The inter-rater reliability was above 70% for every research question, an acceptable level for qualitative studies. (12)

Results

Characteristics of the sample

Table 2 shows the gender and age of adolescents and the education, employment and occupation characteristics of their parents. The participants were similar to the non-participants from the BFS in terms of household type (P = 0.12), mothers' and fathers' education (P = 0.24 and P = 0.19, respectively), mothers' and fathers' employment status (P = 0.33 and P = 0.15, respectively) and mothers' and fathers' occupation (P = 0.73 and P = 0.11, respectively). Few gender differences were found in the adolescents' health and nutrition-related beliefs, attitudes and perceptions, therefore the gender-combined results are presented.

The themes elicited for each research question, and how frequently adolescents talked about them, are shown in Tables 3 and 4 and are discussed below. The adolescents predominantly mentioned health as relating to their physical body and its functional capabilities. Most believed that their health was influenced by lifestyle behaviours (e.g. physical activity, dietary factors, sleeping, drugs and alcohol), and they held the attitude that individuals were responsible for achieving and maintaining good health.

'Body' and 'functional' notions of health

When defining health, most adolescents (n = 25) discussed physical aspects of health, such as being fit or not having an illness. Good health was frequently mentioned as being important for having the ability to perform activities (n = 14). In addition, health was seen as not being restricted in carrying out these physical activities (n = 9).

  [Health is important] for things like going to school, playing sport,
  family and friends, getting out in the community and talking with
  people. (Male, 14)

  [Health] is like being able to go for a jog and not get breathless
  really quickly and stuff, not to be tired. (Female, 13)

Intangible aspects of health, such as mental or emotional wellbeing, were mentioned less frequently, by approximately one-fifth of the adolescents (n = 6). They made reference to factors such as being happy, having plenty of energy and the ability to concentrate.

  [Being healthy is] being emotionally healthy as well, being mentally
  healthy ... (Female, 15)

Health as an outcome of behaviour

Health was discussed as an outcome of undertaking 'healthy' or 'unhealthy' behaviours. Factors external to the adolescents' health behaviours, such as environmental and living conditions, money, availability and accessibility to resources such as health care, shops and sporting equipment, were not mentioned as contributing to health.

Nearly all adolescents (n = 28) mentioned that exercise and dietary factors were important influences on their health. When prompted to talk about which particular dietary factors were most salient, they identified foods (n = 20) and nutrients (n = 14). Other behavioural factors mentioned were getting adequate sleep (n = 5), avoiding alcohol, drugs or tobacco (n = 3) and maintaining personal hygiene (n = 3).

    I think the main contributors toward health would be food, sleep,
    you know everything like drugs, the drug problem has a lot to do
    with it ... (Female, 15)

Parents, social networks and advertising were some of the nonbehavioural influences on health identified by the adolescents. Parents were mentioned as positive role models, by practising healthy lifestyle behaviours (n = 8), and advertising or television programs were seen as both positive and negative influences.

    My mum and dad are important to my health, just the way they eat
    now. My parents have been eating really good lately. Like they're
    into all this health stuff ... (Male, 15)

Importance of the individual

The importance of individual characteristics, such as one's attitude, in influencing health was identified by a small number of adolescents (n = 4). Most of these adolescents talked about their attitude as being important to their health.

    Well, probably the way I feel is one thing. Like when you're a
    little stressed and stuff, you feel sick and that. But I try to stay
    positive and try to just get over stuff and keep going. (Male, 14)

Only a few mentioned the importance of health for external factors. These adolescents (n = 3) talked about not relying on the health-care system:

    [My health is important because] I don't want to have to go to the
    doctors and everything. (Female, 13)

It is interesting to note that nearly half of the sample (n = 13) thought that issues regarding their present health were influential on their future health, and that one-third related the importance of health to their sporting performance.

Describing a healthy diet: characteristics of the whole diet

The adolescents referred to healthy eating on three levels: characteristics of the whole diet, discussion of foods or food groups and nutrient intakes. Balance or moderation were mentioned as constituting a healthy diet by approximately three quarters of the adolescents (n = 22). Balance and moderation were perceived as limiting the consumption of high-fat, high-sugar or 'treat' foods (such as sweets, soft drinks and chocolate).

Many adolescents cited that eating a diet in accordance with dietary recommendations was healthy (n = 18). Most made reference to the Healthy Diet Pyramid, or the recommended daily intakes of specific food groups (such as fruits and vegetables or dairy foods). Skipping meals, especially breakfast, was also discussed as being unhealthy (n = 8). Fresh, natural or unprocessed foods (not frozen, canned, packaged or dried) were identified by a smaller number of adolescents as being the basis to healthy eating (n = 5).

    [A healthy diet is] eating fruits, vegetables, bread, anything with
    carbohydrates actually. I think some sugar and some fat and some
    dairy are good too. I think sugar and fat, a little bit, are
    important for you too. Yeah, I think you should just eat
    occasionally, eat something that you want, treat yourself. (Female,
    15)

    [Describing healthy eating] I'm thinking of the back of the cereal
    box with the food pyramid. Lots of bread, lots of rice ... On the
    bottom is the fruit and the vegetable group and then there's the
    meat group, it's a little bit less than the fruit and bread. Then
    there's the butter and oils, which you have even less of, but they
    are probably still important. (Male, 13)

Describing a healthy diet: foods or food groups

All adolescents (n = 29) mentioned that consuming fruit or vegetables was an important factor in a healthy diet. Many (n = 16) talked about the importance of the breads and cereals group as well as avoiding 'junk foods', such as lollies, potato crisps, pies, sausage rolls, hot dogs, soft drinks and chocolate (n = 16).

Approximately half of the adolescents identified that excluding food groups from the diet may not contribute to good health, in particular, excluding meat (n = 14) or dairy foods (n = 13). Nobody mentioned making healthier choices of meat, such as leaner meats or eating fish occasionally; however, some of the adolescents who mentioned dairy foods did talk about reduced-fat choices being 'healthier' options.

Eating fast foods and takeaways were frequently discussed as being 'unhealthy' (n = 14). About a third of the adolescents (n = 10) mentioned that the foods available in their school canteen were high in fat or sugar. Consuming sugary foods, such as sweets and soft drinks, frequently or in large amounts, was identified by one quarter of the adolescents as being unhealthy (n = 8).

Describing a healthy diet: nutrient intakes

When describing healthy levels of nutrient intakes, the adolescents predominantly discussed fat as impacting on health; other nutrients were mentioned less. A low-fat intake was identified by a high proportion of adolescents as being part of a healthy diet (n = 24). However, no one talked about the different types of fat and their influence on health. Consuming adequate levels of other nutrients, such as carbohydrates, protein, fibre, calcium, iron and water were also discussed frequently (n = 14).

Barriers to healthy eating

The adolescents' perceptions of barriers to healthy eating related to personal, social and structural factors. Of all factors, the most frequently mentioned barriers were taste and convenience (n = 21 and n = 16, respectively). Taste was discussed as being the main factor influencing food choice, and healthier foods were perceived as less tasty. The adolescents also identified that eating healthy food required more time and energy to purchase and prepare. Breaking long-established habits of unhealthy eating was identified as a barrier (n = 8). Some adolescents talked about how the desire to lose weight sometimes lead people to starve themselves or eliminate nutritious foods from their diet (n = 5). Some also said that a lack of knowledge about the diet-disease relationship or the nutrient composition of foods was also a barrier (n = 4).

Many (n = 14) talked about parents or other family members as barriers. If family members did not like healthy foods, they may not be available at home. Some adolescents also discussed parents as barriers if they didn't have enough time to purchase and prepare healthy foods.

    [Some adolescents do not have a healthy eating pattern] probably
    because their parents work late and they have to get their own food
    and they probably get tired of cooking healthy food all the time and
    just order pizza or something unhealthy. (Male, 14)

Peers and friends were also frequently mentioned as barriers (n = 13). These adolescents talked about the culture of some friendship groups and the pressure to conform to these groups as being problematic. Some (n = 8) discussed advertising on TV, magazines and the movies as barriers because they promoted unhealthy foods.

About a third of adolescents identified the price or availability of healthy foods as barriers (n = 9 and n = 10, respectively). All these adolescents perceived healthy food as being more expensive, or not always available in shops or school canteens.

    The healthy things are more expensive in the tuckshop. The salad
    rolls are like $2.40, and that's pretty expensive. Whereas the Mars
    Bars are like $1.30. (Female, 13)

Comparisons between socioeconomic (income) groups were limited, mainly because the adolescents represented a relatively homogeneous group in terms of socioeconomic characteristics. Lower-income adolescents mentioned dietary recommendations, nutrient intakes, dairy foods and avoiding school canteen foods less frequently than their higher-income counterparts. High-income adolescents were also more likely to perceive convenience and family factors less as barriers to healthy eating. The results were also evaluated using other measures of socioeconomic position (SEP), specifically mother's and father's education and occupational status. Our analyses showed that several concepts demonstrated meaningful differences (in the same direction) with two or more of the SEP measures. The definition of health as physical functioning or fitness and as the absence of restrictions occurred more frequently among adolescents from lower socioeconomic backgrounds as identified by two or more SEP measures. Adolescents from lower socioeconomic backgrounds were more likely to perceive their current dietary habits as barriers to eating healthier foods compared with their higher SEP counterparts. There were no additional socioeconomic differences.

Discussion

The present study examined adolescents' health and nutrition-related beliefs, attitudes and perceptions. The adolescents in the present study predominantly defined health in relation to their physical bodies, the existence of restrictions and as a functional entity. They talked about health as a personal characteristic, and as a product of an individual's behaviours. Health was considered important because it was a resource for being able to carry out tasks, and was valued because it meant one could play sport, do better or be more active in school and avoid illness. However, their perception that their current health was also important for their wellbeing in the future was noted. Adolescents predominantly defined a healthy diet as consuming fruits and vegetables, a low-fat intake, having balance or moderation in their diet and eating according to dietary recommendations. The present study also demonstrated that adolescents perceived taste and convenience as the greatest barriers to healthy eating.

A number of studies of adults' lay conceptions of health have yielded similar themes as were elicited in the present study. These studies have demonstrated that health is predominantly perceived as functional capacity or physical fitness, (13-15) as well as showing that adults frequently define health as the absence of illness. (13-15) Somewhat surprisingly, only a modest number of adolescents in the present study mentioned this. Adolescents may be less likely to define health as an absence of illness because, as a population, they experience less morbidity and mortality from illness compared with adults. (2)

There has also been widespread agreement in studies among adults that health is perceived as a physical concept, and that fewer people talk about its psychological or social aspects. (16) Few studies have explored adolescents' perceptions of factors influencing health; however, the findings of the present study are consistent with similar research among adults that has emphasised behavioural factors as most influential on health. (13) These 'physical' conceptions of health, and the perceived importance of behavioural factors and the individual, may reflect the nature of health education and promotion programs. These generally focus on 'concrete' aspects of health, target changes in people's behaviour and encourage individuals to be pro-active in terms of their health (13)

The adolescents' responses about what constitutes a healthy diet were comparable to those found in studies among adults (17) and other adolescents. (8,18,19) Eating more fruits and vegetables, consuming less fat and balance/moderation all form the basis of the Australian Dietary Guidelines for Children and Adolescents and other nutrition-promotion messages. (3,20) Therefore, the adolescents demonstrated a broad awareness of the recommendations promulgated in these population-based nutrition guidance strategies. Despite this, Australian adolescents have not adopted behaviours promoted by these messages, and still have intakes of total fat, saturated fat, fruits and vegetables that are not in accordance with recommendations for chronic disease prevention. (5,6) This is not surprising, given that nutrition knowledge has only been shown to be weakly related to dietary behaviour. (21,22) Other factors may contribute to adolescents' dietary behaviour, as articulated by the Theory of Planned Behaviour, for example adolescents subjective norms (i.e. their evaluation of whether important people in their lives have a healthy diet) (8) and their perceived behavioural control (21,23) have been shown to be good predictors of dietary behaviour. The influence of these factors on dietary behaviour are worthy of further qualitative investigation among adolescents in Australia.

The lower levels of awareness of dietary recommendations among adolescents from lower-income backgrounds observed in the present study may be due to these groups not being exposed to as much health information compared with their more advantaged counterparts. Although there are many limitations to making comparisons between socioeconomic groups in the present study (see below), these differences may be important factors that contribute to socioeconomic inequalities in fruit and vegetable consumption among Australian adolescents. (18)

The fact that the most commonly mentioned barriers to healthy eating were taste and convenience suggests that adolescents regard healthy eating as being difficult to achieve and that it requires great changes to one's food preferences and lifestyle. These perceptions may reduce the likelihood that adolescents adopt and maintain healthy dietary behaviours. This finding also reflects the fact that taste preference is the strongest predictor of food choice. This is consistent with other studies that have reported taste as being one of the most important determinants of food choice among adolescents. (8,19,24-26)

In light of the current concern about the rapid increase in the number of children and adolescents who are overweight or obese, it is interesting to note that nearly all those interviewed recognise that diet and physical activity impact on their health, whereas factors such as television and advertising are perceived by only about one quarter as having either a positive or negative effect. Environmental influences, such as lack of access or availability, were rarely mentioned.

Study limitations

A number of limitations in the present study need to be acknowledged. The adolescents were a convenience sample from a larger study. Although this sample was similar in terms of the socioeconomic characteristics of participants in the larger study, the parents (and/or adolescents) who volunteered may have had a particular interest in health and/or nutrition. Therefore, it is uncertain whether the results of the present study only represent the beliefs, attitudes and perceptions of this select group of adolescents; however, a range of views were expressed by the participants. The sample was relatively homogeneous in terms of socioeconomic characteristics, limiting the ability to make firm comparisons and conclusions between socioeconomic groups.

It cannot be judged how deeply or sincerely the adolescents held the beliefs and perceptions that they articulated. However, expression of their true beliefs was encouraged by withholding judgemental comments and by reinforcing that there were no right or wrong answers to the questions.

Implications of findings

The results of the present study have several implications for health promotion and research. The principal findings demonstrate that adolescents are knowledgeable about behavioural risk factors, and regard their health as an important factor in their lives. Therefore, lack of knowledge about risk factors or a low priority of health may not contribute to the uptake of risk behaviours in this age group. The fact that most adolescents mentioned the broad characteristics of a healthy diet and did not identify knowledge as a barrier to healthy eating suggests that nutrition-promotion initiatives should not concentrate solely on the provision of nutrition information. These efforts may be more effective if they attempt to improve adolescents' perceptions of healthy eating in terms of taste and convenience. Strategies may involve promoting fast and easy-to-prepare meals that are healthy. Nutrition-promotion programs might emphasise that eating a healthy diet does not always involve compromising on taste.

Acknowledgements

The authors wish to acknowledge the interviewers in the BFS for recruiting participants for the present study. We would also like to acknowledge Trish Gould and Belinda Hewitt for their help in testing the reliability of the coding. Dr Giskes is supported by a National Health and Medical Research Council Sidney Sax International Post-Doctoral Fellowship (ID number 290540). Dr Turrell is supported by a National Health and Medical Research Council/National Heart Foundation Career Development Award (CR 01B 0502).

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24. Brug J, Lechner L, De Vries H. Psychosocial determinants of fruit and vegetable consumption. Appetite 1995; 25: 285-96.

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Centre for Health Research--Public Health, Queensland University of Technology, Brisbane

K. Giskes, BHlthSc (Nutr & Diet) (Hons), PhD

C. Patterson, MSc, PhD, GradDipBusAdmin, Research Director, School of Public Health

G. Turrell, BA, MQual, PhD

B. Newman, MS, PhD, Professor of Public Health

Department of Public Health, Erasmus Medical Center, Rotterdam

K. Giskes, BHlthSc (Nutr & Diet) (Hons), PhD

Correspondence: K. Giskes, Department of Public Health, Erasmus Medical Center, PO Box 1738, 3000DR Rotterdam, the Netherlands. Email: [e-mail]

K. Giskes is a postdoctoral researcher supported by a National Health and Medical Research Council Sidney Sax Fellowship (ID 290540). G. Turrell is a senior research fellow supported by a National Health and Medical Research Council/National Heart Foundation Career Development Award (CR 01B 0502).

Table 1. Questions and examples of probes used in the interview guide

Theme and question                Example probes

Definition of health
What does being healthy mean to   Can you explain what you mean by that?
  you?
Factors influencing health
What do you think are the main    Why do you say that?
  things that make you healthy?
Importance of health
Is your health important to you   Can you talk about why this is so?
  at the moment?
Definition of 'healthy diet'
How would you describe healthy    Can you explain what you mean by that?
  eating?
Barriers to healthy eating
In you opinion, what stops some   Why do you say that?
  teenagers from eating healthy   Can you talk about why this is so?
  foods?

Table 2. Socio-demographic characteristics of participating and
nonparticipating adolescents and their parents

                                Participants  Non-participants
                                n (%)         n (%)

Adolescents' characteristics
Gender
  Male                          16 (55)       23 (49)
  Female                        13 (45)       27 (57)
Age (years)
13                               9 (31)       13 (26)
14                              13 (45)       22 (44)
15                               7 (24)       15 (30)
Household type
Couple-parent household         26 (90)       44 (88)
Single-parent household          3 (10)        6 (12)
Parents' characteristics
Mother's education
  Bachelor degree or higher      6 (21)       10 (20)
  Diploma                        1 (3)         6 (12)
  Vocational                     7 (24)       10 (20)
  No postschool qualifications  15 (52)       24 (48)
Father's education (a)
  Bachelor degree or higher      6 (23)       12 (26)
  Diploma                        1 (4)         4 (9)
  Vocational                    12 (46)       20 (43)
  No postschool qualifications   7 (27)       10 (22)
Mother's employment status
  Full-time                      5 (17)       16 (32)
  Part-time                     14 (48)       18 (36)
  Not in labour force           10 (34)       16 (32)
Father's employment status (a)
  Full-time                     19 (73)       28 (61)
  Part-time                      4 (15)        9 (20)
  Not in labour force            3 (12)        9 (20)
Mother's occupation
  Managers, professionals        8 (28)       12 (24)
  White-collar                   9 (31)       13 (26)
  Blue-collar                    2 (7)         9 (18)
Father's occupation (a)
  Managers, professionals       10 (43)       21 (57)
  White-collar                   3 (13)       14 (38)
  Blue-collar                   10 (43)        2 (5)
Household income (b)
  Low                           13 (45)       22 (44)
  High                          16 (55)       28 (56)

(a) Excludes adolescents in single-mother households (n = 3 in the
participant group, n = 4 among nonparticipating adolescents).
(b) Low household income was defined as gross annual household income of
[less than or equal to]S41599 ($AUS). Those with an income greater than
this were in the high-income group.

Table 3. Themes elicited from adolescents' health-related beliefs and
perceptions

                                           Total (n = 29)
Themes and codes                           n (%)

Definition of health
Physical functioning or fitness            14 (48)
Not having any restrictions                 9 (31)
Not having any illnesses                    8 (28)
Mental/emotional wellbeing                  6 (21)
Mental/emotional functioning                6 (21)
Factors influencing health
Diet (general)                             28 (97)
Physical activity                          28 (97)
Diet (specific foods/food groups)          20 (69)
Diet (specific nutrients)                  14 (48)
Other people/TV/advertising                 8 (28)
Weight                                      7 (24)
Sleep                                       5 (17)
Attitude                                    4 (14)
Alcohol, tobacco, elicit drugs              3 (10)
Social support and social networks          3 (10)
Personal hygiene                            3 (10)
Emotions                                    2 (7)
Illness                                     2 (7)
Importance of health
Don't want to get sick                     14 (48)
Maintaining health in the future           13 (45)
Sport                                      10 (34)
Don't want to gain weight                   7 (24)
School                                      6 (21)
Day-to-day functioning                      5 (17)
Being able to reach goals or potential      5 (17)
Quality of life                             4 (14)
Don't want to increase use of health care   3 (10)

Table 4. Themes elicited from adolescents' diet-related beliefs,
attitudes and perceptions

                                               Total
                                               (n = 29)
Themes and codes                               n (%)

Definition of 'healthy diet'
Characteristics of the whole diet
  Balance or moderation in the diet            22 (76)
  Eating according to recommendations          18 (62)
  Not skipping meals                            8 (28)
  Eating fresh, natural or unprocessed foods    5 (17)
Foods or food groups
  Consuming fruits or vegetables               29 (100)
  Eating breads or cereals                     16 (55)
  Not having 'junk foods' regularly            16 (55)
  Not excluding meat                           14 (48)
  Not excluding dairy foods                    13 (45)
  Not having fast foods frequently             14 (48)
  Not having school canteen foods regularly    10 (34)
  Not consuming large amounts of sugary foods   8 (28)
Nutrient intakes
  Consuming a low-fat diet                     24 (83)
  Healthy levels of nutrient intakes           14 (48)
Barriers to healthy eating
Personal barriers
  Taste                                        21 (72)
  Convenience                                  16 (55)
  Do not think about/value health               9 (31)
  Habit                                         8 (28)
  Wanting to lose weight                        5 (17)
  Knowledge                                     4 (14)
Social barriers
  Family                                       14 (48)
  Friends or peers                             13 (45)
  Advertising/or other media                    8 (28)
Structural barriers
  Availability                                 10 (34)
  Price                                         9 (31)