2 ADOLESCENCE PROVIDES A WINDOW OF OPPORTUNITY FOR NUTRITION A transitional period between childhood and adulthood.adolescence provides an opportunity to prepare for a healthy productive and reproductive life.and to prevent the onset of nutrition-related chronic diseases in adult life,while addressing adolescence-specific nutrition issues and possibly also correcting some nutritional problems originating in the past. 2.1 Adolescence is a timely period for the adoption and consolidation of sound dietary habits Adolescents are usually open to new ideas;they show curiosity and interest.Many habits acquired during adolescence will last a lifetime.Furthermore,with increasing age,adolescents'personal choices and preferences gain priority over eating habits acquired in the family,and they have progressively more control over what they eat,when and where(Thomas 1991;Shepherd and Dennison,1996;Spear 1996). One expression of adolescents'search to establish themselves as autonomous members of society is through a change in eating habits.For these reasons,adolescents are an ideal target for nutrition education. In younger children,parents are in charge and need to be influenced.In adults,it may be more difficult to modify well-established patterns.Furthermore,adolescents may not only adopt healthy eating patterns and lifestyles for themselves,but also influence their peers,family and other community members. Changes in lifestyle,including food habits,are often more obvious among urban adolescents,(Ahmed et al,1998),as they are typically the 'early adopters'owing,among other things to their attraction for novelty and high exposure to commercial marketing in cities.Indeed,looking into adolescents'living and eating patterns may give an idea of the changes taking place in a society.They may act as role models for others in the community,in particular if they are from higher socioeconomic status groups. In this sense,the patterns seen in urban well-off adolescents anticipate the patterns of the future.Since these privileged youth are a reference group for other adolescents,they should also be targeted by health and nutrition promotion activities. 2.2 Improving adolescents'nutrition behaviours is an investment in adult health Adolescents are in the process of establishing responsibility for their own health-related behaviours, including diet.It is therefore an appropriate time for health promotion programmes based on documented relationships between behaviour in this age group,obesity,cardiovascular and other chronic disease risk factors(see Chapter 3).Adolescents can and should take responsibility for their nutrition and the long-term repercussions on health.This may be quite a challenge,considering that adolescents tend to be little concerned with the future(Greene 1986),and long-term consequences of their present behaviours (Cordonnier 1995),but relevant strategies exist,based on an appropriate knowledge of personal and environmental determinants of food choice in this age group. Nutrition is only one aspect of health behaviours and the development of these in relation with chronic disease is better conceptualized in a 'chain of risk'framework(Kuh et al,1997).Over the life course, there may be an accumulation of biological and social risk.For instance,poor foetal nutrition(Barker et al,1990;Barker 1996),in combination with inadequate or adverse influence of parents,peers and the educational experience in childhood and adolescence,sets the stage for chronic disease in adult life, with additional risk coming from cultural influences and lifestyles.In other words,beyond biological NUTRITION IN A DO LESC E N CE /7NUTRITION IN ADOLESCENCE / 7 2 ADOLESCENCE PROVIDES A WINDOW OF OPPORTUNITY FOR NUTRITION A transitional period between childhood and adulthood, adolescence provides an opportunity to prepare for a healthy productive and reproductive life, and to prevent the onset of nutrition-related chronic diseases in adult life, while addressing adolescence-specific nutrition issues and possibly also correcting some nutritional problems originating in the past. 2.1 Adolescence is a timely period for the adoption and consolidation of sound dietary habits Adolescents are usually open to new ideas; they show curiosity and interest. Many habits acquired during adolescence will last a lifetime. Furthermore, with increasing age, adolescents’ personal choices and preferences gain priority over eating habits acquired in the family, and they have progressively more control over what they eat, when and where (Thomas 1991; Shepherd and Dennison, 1996; Spear 1996). One expression of adolescents’ search to establish themselves as autonomous members of society is through a change in eating habits. For these reasons, adolescents are an ideal target for nutrition education. In younger children, parents are in charge and need to be influenced. In adults, it may be more difficult to modify well-established patterns. Furthermore, adolescents may not only adopt healthy eating patterns and lifestyles for themselves, but also influence their peers, family and other community members. Changes in lifestyle, including food habits, are often more obvious among urban adolescents, (Ahmed et al, 1998), as they are typically the ‘early adopters’ owing, among other things to their attraction for novelty and high exposure to commercial marketing in cities. Indeed, looking into adolescents’ living and eating patterns may give an idea of the changes taking place in a society. They may act as role models for others in the community, in particular if they are from higher socioeconomic status groups. In this sense, the patterns seen in urban well-off adolescents anticipate the patterns of the future. Since these privileged youth are a reference group for other adolescents, they should also be targeted by health and nutrition promotion activities. 2.2 Improving adolescents’ nutrition behaviours is an investment in adult health Adolescents are in the process of establishing responsibility for their own health-related behaviours, including diet. It is therefore an appropriate time for health promotion programmes based on documented relationships between behaviour in this age group, obesity, cardiovascular and other chronic disease risk factors (see Chapter 3). Adolescents can and should take responsibility for their nutrition and the long-term repercussions on health. This may be quite a challenge, considering that adolescents tend to be little concerned with the future (Greene 1986), and long-term consequences of their present behaviours (Cordonnier 1995), but relevant strategies exist, based on an appropriate knowledge of personal and environmental determinants of food choice in this age group. Nutrition is only one aspect of health behaviours and the development of these in relation with chronic disease is better conceptualized in a ‘chain of risk’ framework (Kuh et al, 1997). Over the life course, there may be an accumulation of biological and social risk. For instance, poor foetal nutrition (Barker et al, 1990; Barker 1996), in combination with inadequate or adverse influence of parents, peers and the educational experience in childhood and adolescence, sets the stage for chronic disease in adult life, with additional risk coming from cultural influences and lifestyles. In other words, beyond biological