Definitions:-Leading organizations in the field of disease prevention and health promotion, such as the World Health Organization (Headquarters in Geneva, Switzerland) and the Centers for Disease Control (Atlanta, USA), have since the early 1980s used healthy lifestyles as a label for a cluster of behaviours known to reduce the risk of injury, morbidity and mortality and increase the chances of good health and well-being. Health-related behaviours (health-enhancing or health- compromising) include eating habits, physical exercise, smoking, alcohol use, use of illegal addictive substances, sexual practices, risk-taking in traffic, work etc., use of safety devices (for instance wearing safety helmets when biking), sleeping habits, oral hygiene and personal hygiene. Examples of health-related behaviours which are relevant only to specific ethnic groups are exposure to the sun in order to obtain a more tanned skin among Caucasians, or use of skin-whitening creams among ethnic groups with dark skin colours.
The concept of lifestyle is also used in other contexts. In the field of marketing, analysis of consumer lifestyles means examining the way people live (their activities, interests, values and opinions) in order to better tailor marketing efforts to specific target groups.
According to Elliott (1993):
. . . a lifestyle has been defined as a distinctive mode of living that is defined by a set of expressive, patterned behaviors of individuals occurring with some consistency over a period of time.
It should be evident from this definition that the lifestyle construct is not meant to capture the totality of a person’s behaviour. There are three aspects that make lifestyles more specific: their consistency or relative stability over time, their interrelatedness (being patterned), and the meaning they convey to others as well as oneself (expressiveness). Health-related lifestyles refer to behav- iours that have been shown by epidemiological and other health research to predict disease or health. A related term, ‘risk-taking behaviour’, refers to behaviour patterns which are volitional and which increase risk of disease of injury (Irvin, 1990).
The lifestyle concept is less accepted as a term in developing coun- tries. In Lalonde’s classic report on ‘The health of Canadians’ (Lalonde, 1974) the definition of lifestyle that was suggested implied that lifestyles are the result of choices made by individuals. The lifestyle of an individual is seen as the result of an aggregate of decisions made by the person him- or herself, decisions over which the person has considerable control. Environmental and social fac- tors have, however, been shown to exert a powerful influence on health behaviours, even in affluent societies, and factors over which the individual person has limited or no control are obviously of even higher importance in developing countries (Eaton et al., 2004).
When defining ‘adolescence’, several criteria are relevant, for ins- tance secondary sex characteristics, cognitive abilities, social criteria or simply age. According to Adams et al. (1994), adolescence covers the age-groups 11–20, and distinction is made between early ado- lescence (11–14), middle adolescence (15–17) and late adolescence (18–20). There is no global consensus regarding the definition of adolescence. The World Health Organization defines adolescence as the period from 10 to 19 years of age.
Defining adolescence as a period covering such a wide age-range may seem particularly relevant for affluent societies of the West. During recent decades, however, it has become clear that a transi- tional stage between childhood and adulthood is evident in most societies of the world. This expanded, more-distinct transitional period includes longer schooling, earlier puberty, later marriage, removal from full-time labour, and greater separation from the world of adults (Larson & Wilson, 2004). During this period of life, through a complex interplay between biological, physiological, psychological, social, societal and cultural factors, lifestyles are shaped.
Health behaviour change during adolescence:-
During adolescence a number of health-compromising behaviours emerge. When entering adolescence, children are normally sponta- neously physically active, and there is hardly any use of tobacco, alcohol or other addictive substances. When leaving adolescence, a substantial proportion of adolescents are physically inactive, have started smoking, and some have started using illegal addictive sub- stances. The sexual debut usually takes place during adolescence, and being sexually active without adequate protection against unwanted pregnancies and sexually transmitted diseases, including HIV/AIDS, represents a serious threat to health and wellbeing.
According to a report from the World Health Organization interna- tional study on Health Behaviour in School-Aged Children (HBSC), the proportion of smokers increases during early adolescence (Currie et al., 2004). At age 11 the average proportion of smokers (smoking daily or weekly) across all samples (35 countries) is 2%, at age 13 it is 8%, and at age 15 it is 24%. The differences between boys and girls for all countries combined (mainly European countries plus Canada and the United States) were negligible. Corresponding figures for weekly alcohol consumption are 5, 12 and 29%. More boys than girls used alcohol weekly at age 15 (34 and 24% respectively).
Prochaska et al. (2001) have developed a screening instrument which defines ‘moderate-to-vigorous physical activity’ (MVPA). Their definition was applied to data from the HBSC study. The pro- portion of young people meeting the MVPA guidelines on physical activity was (across all samples) 38% at age 11 and 29% at age 15; in other words there is a marked decrease with age that most likely continues across the remaining years of adolescence as well as into early adulthood (Stephens et al., 1984). Food habits were also cov- ered by the HBSC survey. The proportion of adolescents who eat fruit daily decreases from 38% among 11 year olds to 29% among the 15 year olds (Currie et al., 2004).
Thuen et al. (1992) have shown that use of safety equipment (seat belts, bicycle helmets, reflectors, life jackets) drops dramatically during early adolescence, and the proportion involved in behaviour associated with elevated risks of accidents and injuries increases.
It must be kept in mind, however, that a majority of young peo- ple never become regular smokers, heavy drinkers or drug addicts, and a substantial proportion of young adults remain physically active and continue eating healthy food throughout and after the adolescent years. During adolescence the basis for a lifelong health- enhancing lifestyle may be established.
The effects of health-compromising behaviours during adoles- cence can be short-term as well as long-term. Drink driving increases the risk of dramatic and fatal accidents, and represents a major short-term threat to young people’s health and lives. Daily smoking may lead to coronary heart disease and lung cancer, but these effects usually become visible only after many years of expo- sure. The importance of promoting healthy lifestyles among ado- lescents therefore to some extent depends on the stability of such behaviours. The higher the stability, the more important it is to promote healthy lifestyles at a young age.
Jessor et al. (1991) have studied the stability of problem behaviours from adolescence to adulthood, and conclude that there is consid- erable stability and continuity. They claim that ‘the adolescent is parent of the young adult’.
Although few research projects have focused on the stability and change of physical activity from childhood to adolescence, there is one study which concludes that the level of physical activity in childhood and adolescence to some extent predicts the level of physical activity later in life (Anderssen et al., 1996). Other studies of longitudinal tracking of behaviours (physical activity, food pref- erence and smoking behaviour), have provided convincing evidence that behaviours established during early adolescence do predict behaviours measured during late adolescence and beyond (Klepp, 1993; Kelder et al., 1994; Telama et al., 1997). Substantial tracking has also been found for body mass index over an 18 years’ age span (from 15 to 33 years) (Kvaavik et al., 2003).
The promotion of healthy lifestyles among young people is obvi- ously important, not only because of its short-term impact on health and wellbeing, but also because of its consequences for health- related behaviours later in life.
Clusters of health behaviours:-
A number of studies have examined to what extent health behaviours are intercorrelated, and to what extent these correlations reflect underlying clusters or dimensions. Analyses from the international study on Health Behaviour in School-Aged Children indicated two such underlying dimensions: (a) addictive and risk- taking behaviours and (b) health-enhancing behaviours (Nutbeam et al., 1991; Aarø et al., 1995). The correlation between the two factors was negative and estimates varied from approximately 0.40 to 0.50. Within these two ‘second order factors’, sub-clusters of health-related behaviours could also be identified. Røysamb et al. (1997) identified factors at three levels, a multidimensional level with a number of specific factors, a few-dimensional level with three broad factors, and finally a general factor encompassing the three broad factors. The three broad factors were ‘High action’, ‘Addiction’ and ‘Protection’.
The addictive dimension corresponds well with Richard Jessor’s ‘problem behaviours’ (Jessor & Jessor, 1977; Jessor, 1984). He claims that a number of health-related behaviours reflect a ‘syndrome’, or an underlying tendency to behave defiantly and unconvention- ally. He includes such behaviours as use of alcohol, marijuana and tobacco, and he maintains that these are associated with a higher likelihood of involvement in other types of risk behaviour, such as precocious sexual activity, aggression and delinquency. Jessor maintains that for these behaviours the pattern of associations with a number of personality and social environmental correlates is essentially the same.
Health-enhancing behaviours, which in some studies form a second factor, include physical activity, consumption of healthy food, oral hygiene, use of safety devices (seat belts, reflectors, etc.) and use of vitamins. The diffusion of innovation processes, which have been described by Everett Rogers, may serve as a framework for explaining why such behaviours are intercorrelated (Rogers, 2003). If we assume that health-education and health-promotion activities reach and influence health behaviours in certain individuals and certain groups to a larger extent than in other individuals and other groups, correlations among a range of health-enhancing behaviours tend to emerge.
Intercorrelations and clusters of intercorrelations among health- behaviour variables imply that they do not exist as independent and unique domains. Their interrelatedness indicates the usefulness of the notion of ‘lifestyles’. It may be argued that such intercorrelations indicate similarities in the processes underlying different health behaviours. Furthermore, intercorrelations between health behaviours imply overlap in target groups across behavioural risk factors, and support the notion of a more integrated and holistic approach to health promotion among adolescents (Nutbeam et al., 1991).
Predictors and correlates of health behaviours:-
A number of conceptual models and theories are relevant in order to identify factors and processes that influence health-related behav- iours. The mainstream of health behaviour research is dominated by social cognition models (Rutter & Quine, 2002; Conner & Norman, 2005). A group of experts at a meeting organized by the National Institute of Health (NIH) came to the conclusion that the most important predictors were intentions, skills, environmental con- straints, anticipated outcomes (or attitudes), social norms, self effi- cacy, self-standards and emotions (Fishbein et al., 2001). They did not reach consensus regarding any specific theoretical or conceptual model by which these factors could be arranged into a single causal system. Among the most influential theories are Social Cognitive Theory (Bandura, 1986) and the Theory of Planned Behaviour (Ajzen, 1988). Ajzen assumes that a specific behaviour is determined to a large extent by intentions to perform the behaviour, and that such intentions are influenced by personal attitudes to the behaviour, subjective norms and perceived behavioural control. Rather than simply assuming that such factors as attitudes and perceived behav- ioural control are predictors, while behaviours are outcomes, we must suppose that there is an ongoing and continuous process of reciprocal determinism (Bandura, 1986). Bandura sees behaviours as shaped by an ongoing process of interrelationships with personal and environmental factors. Key concepts in Bandura’s analyses of health behaviours are goals (proximal and distal), outcome expecta- tions and self-efficacy (Bandura, 1998; 2005).
Although the major determinants of health-related lifestyles among adolescents are social, some personality characteristics have been shown to be consistently associated with ‘problem behaviours’. Jessor claims that in the personality system, the main characteristics of proneness to problem behaviour include placing a lower value on academic achievement and lower expectations of academic achievement (Jessor, 1984). The sensation-seeking personality trait (Zuckermann, 1979) has been shown to correlate with such problem behaviours as smoking, alcohol consumption, number of lifetime sex partners and experience of casual sex (Kraft & Rise, 1994).
The cross-cultural relevance of theories and conceptual models for prediction of health behaviours developed in western countries has repeatedly been questioned (Campbell, 2003). Jessor et al. (2003), in a study of predictors of problem behaviours among ado- lescents in the United States and China, came to the conclusion that although the levels of problem behaviours may be different, the same set of predictors (protective factors and risk factors) seem to be relevant in these two widely different societies and cul- tures. The relevance of social cognition models in an African context is currently being examined in a large-scale multi-site study of sexual and reproductive behaviours (Aarø et al., 2006).
Structural and demographic factors:-
Health-compromising lifestyles are to a large extent a product of the modern world. Physical inactivity is fostered by modern means of transport and by passive exposure to TV channels, DVD movies, internet use and PC games. Widespread use of addictive substances may reflect a weakening of social norms and the deterioration of social networks. Broken families and family problems may lead to reduced parental control over food habits, sleeping habits and use of addictive substances.
Changes in health behaviours do not take place at the same speed and simultaneously in all groups. In the industrialized countries the use of tobacco first became widespread among men and among high-status groups. Presently, high-status groups have reduced their use of tobacco substantially. Low-status groups are falling behind, and in many countries the prevalence of regular smokers in low-status segments of the population is 3–4 times higher than among those belonging to high-status segments (Ferrence, 1996). Similar processes can be observed for other health behaviours. Belonging to high-status groups means that you are also more likely to be physically active, to eat healthy food and to wear seat belts, just to mention some examples.
Since health behaviours of adolescents are closely related to those of their parents, similar socioeconomic inequalities may exist for adolescents as well. Adolescents are in a process of transition from having their socioeconomic status defined by their parents’ education, income and jobs towards having their socioeconomic status defined by their own position in the societal structure. Several studies have reported rather moderate or weak associations between parents’ level of education and offspring’s health behav- iours (Friestad & Klepp, 2006). Problems with obtaining valid and reliable measurements of parents’ level of education may have contributed to reducing the strength of associations. Adolescents’ relationship to school and education has sometimes been used as an indicator of their socioeconomic position. Friestad & Klepp (2006) found consistent associations between educational aspira- tions and composite measures of health behaviour (low aspirations predicting high scores on health-compromising behaviours and low scores on health-enhancing behaviours). Nutbeam et al. (1988; 1993) found strong associations between school alienation and use of addictive substances (tobacco and alcohol). This indicates that a socioeconomic gradient in lifestyles also exists for adolescents. Researchers have concluded that health-related behaviours to some extent carry over from one generation to the next, and that a process of social reproduction of socioeconomic inequalities in lifestyles can be demonstrated (Wold, 1989; Ketterlinus et al., 1994). Other researchers have found empirical support for adoles- cent lifestyles being predictive of future socioeconomic status (Koivusilta et al., 1999).
Health behaviours are also influenced by such factors as adver- tising, legislation (including bans on advertising), price and availabil- ity of products. Increasing the price of tobacco products leads to a decrease in consumption, and this decrease is higher among adolescents than among adults. Among adults the price elasticity is probably close to 0.5. A price elasticity of 0.5 means that increas- ing the price by 10% leads to a 5% reduction in consumption. The price elasticity is particularly high among young people. In one study it was shown to be 1.40 among 12–17 year olds (Warner, 1986).
The effects of tobacco advertising and the effects of banning such advertising on smoking habits of adolescents have been debated.
The tobacco industry has aggressively defended their right to market legal products, while health authorities, health professionals and non governmental organizations have argued that bans on all kinds of tobacco advertising are necessary in order to reduce smoking among adolescents. An increasing body of research gives both theoretical and empirical evidence for a causal relationship between advertising and use of tobacco, and it is likely that ‘the dynamic tobacco market represented by children and adolescents’ is the main target of tobacco sales promotion (Rimpela ̈ et al., 1993). Braverman & Aarø (2004), in a study among adolescents, found that even low levels of exposure to tobacco marketing was associated with stronger expectations of future smoking, after controlling for present smoking habits and important social predictors of smoking. Longitudinal studies have consistently shown that exposure to tobacco advertising is associated with increased risk that adolescents will start to smoke (Lovato et al., 2003). It is reasonable to assume that effectively enforced bans on advertising contribute to reducing smoking among adolescents. In order to make the healthy choices the easiest ones, the prices of healthy products should be kept low, the prices of unhealthy products should be high, and for young people in particular, the availability of unhealthy products like alcohol and cigarettes should be limited as much as possible.
Health-behaviour interventions targeting adolescents take place in the mass media, schools and communities. Examples of programmes that have not proven effective are numerous. There are also, however, examples of well-designed and research-based interventions that have had substantial effects. Kirby & Coyle (1997) reviewed 35 evalua- tions of school-based sexual education programmes, and found that a few programmes had contributed to delaying the onset of inter- course, reduced the frequency of intercourse, reduced number of sexual partners, or increased the use of condoms or other contracep- tives. For the majority of the programmes, however, no statistical effects on risk-taking behaviours were observed. Thomas (2002) reviewed 76 randomized controlled trials of school-based interven- tions to prevent smoking. Among interventions based on the social influence approach, which has been regarded as the most effective approach to smoking prevention among adolescents, half of the stud- ies showed statistically significant effects of the interventions. Jøsendal et al. (2005) found that a three-year programme based on the social-influence model reduced the prevalence of smoking by about 30%. Positive results have also been found for school-based interventions to reduce drug use (Faggiano et al., 2005).
There is less strong evidence for positive effects of mass-media and community-based interventions (Sowden & Arblaster, 1998; Sowden et al., 2003). This does not necessarily mean that such inter- ventions are ineffective. Planning and conducting studies with strong research designs and demonstrating significant effects of interventions is much easier in schools than in most other settings. In addition, programmes which have no visible immediate effects on behaviour, may contribute to raising awareness, and changing
beliefs, attitudes and social norms, and they may lead to increased support for restrictive and societal measures. Such indicators of change may, in the long term, trigger processes that are just as important for behaviour change in populations as programmes that succeed in bringing about immediate effects on behaviour.
Adolescents in developing countries:-
Among 1.2 billion adolescents worldwide, about 85% live in devel- oping countries, and this proportion is increasing. Also, in the devel- oping world, health-compromising lifestyles are gradually becoming a threat to health, and in developing countries such behaviours become more prevalent during adolescence. Research has shown that increasing production and consumption of alcohol is taking place in both rural and urban areas in Africa (Maula et al., 1988). Parallel with the reduction in tobacco smoking in Western Europe and North America, effective marketing contributes to increasing the prevalence of smoking in developing countries and in Eastern Europe (World Bank, 1999).
Eide & Acuda (1996) in a study from Zimbabwe showed that cul- tural influences from industrialized countries are accompanied by introduction of forms of alcohol use which are less well regulated by rituals and social norms than the use of traditional beverages. Young people with a ‘western’ cultural orientation have alcohol preferences which are different from those with a more traditional cultural orientation, and their consumption is higher. Similar cul- tural influences may operate on a variety of health behaviours, and the introduction of a ‘modern’ lifestyle may lead to a gradual increase in diseases which used to be typical of western countries. This adds health burdens and economic burdens to nations which are already confronted with infectious diseases (including the AIDS pandemic) and overwhelming health problems caused by poverty, poor housing, malnutrition, inadequate sanitation and lack of clean water.
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