I■■■■■■■■WHO DISCUSSION PAPERS ON ADOLESCENCE Nutrition in adolescence Issues and Challenges for the Health Sector Issues in Adolescent Health and Development World Health Organization HYO
Nutrition in adolescence – Issues and Challenges for the Health Sector Issues in Adolescent Health and Development CAH NUTRITION WHO DISCUSSION PAPERS ON ADOLESCENCE
Contents l.NTRODUCTION… 1.1 Adolescents:Who are they?.............. 1.2 Increasing focus on adolescent health and well-being................. …2 1.3 Objectives and content of the paper. 2.ADOLESCENCE PROVIDES A WINDOW OF OPPORTUNITY FOR NUTRITION ............. 2.1 Adolescence is a timely period for the adoption and consolidation of sound dietary habits …7 2.2 Improving adolescents'nutrition behaviours is an investment in adult health ............. 2.3 There is potential for correcting nutritional inadequacies and perhaps even for catch-upgT0wth…8 2.4 Nutrition intervention in adolescent girls may contribute to breaking the vicious cycle of intergenerational malnutrition,poverty and chronic disease..9 2.5 Reaching households and communities through adolescents...............10 3.ADOLESCENCE IS A PERIOD OF NUTRITIONAL VULNERABILITY.11 3.1 Conceptual framework for the analysis of nutritional problems in adolescence.....11 3.2 Nutritional problems in adolescence.13 3.2.1 Undernutrition,stunting and consequences in adolescence...14 3.2.1.1 Overview on malnutrition in adolescence...............................14 3.2.1.2 Malnutrition delays physical growth and maturation.....16 3.2.1.3 Stunting and delayed maturation compound risk of adolescent pr gnancy.l6 3.2.1.4 Malnutrition reduces work capacity .......... .16 3.2.2 Iron deficiency anaemia and other widespread micronutrient deficiencies.......17 3.2.2.1 Iron deficiency and anaemia.17 3.2.2.2 Vitamin A deficiency20 3.2.2.3 lodine deficiency disorders......... 20 3.2.2.4 Micronutrient deficiencies and bone disease ..............2o 3.2.3 Obesity and other nutrition-related chronic diseases..2. 3.2.31 3.2.3.2 Cardiovascular disease risks.24 3.2.3.3 Nutrition,gout and gallstones......... 25 3.2.3.4 Nutrition and cancer26 3.2.4 Tooth decay,a nutrition-related problem in adolescence........... .27 3.3 Early pregnancy,a well-documented factor of health and nutritional risk in adolescent grlS…,27 3.3.1 Maternal mortality and morbidity28 3.3.2 Low birth weight and prematurity29 3.3.3 Lactational performance ... 29 3.3.4 Socioeconomic consequences and correlates............. 30 3.4 Lifestyle and eating patterns,major threats to adolescents'nutritional status......31 3.4.1 Typical eating patterns and intakes of adolescents.31 3.4.2 Commercial,cultural and psychosocial influences on eating patterns........32 N UTR IT I O N I N A DO L ES C E N C E /ii
N U T R I T I O N I N A D O L E S C E N C E /iii Contents 1. INTRODUCTION ............................................................................................................................... 1 1.1 Adolescents: Who are they? ..................................................................................................... 1 1.2 Increasing focus on adolescent health and well-being .......................................................... 2 1.3 Objectives and content of the paper ....................................................................................... 4 2. ADOLESCENCE PROVIDES A WINDOW OF OPPORTUNITY FOR NUTRITION .................. 7 2.1 Adolescence is a timely period for the adoption and consolidation of sound dietary habits ......................................................................................................................................... 7 2.2 Improving adolescents’ nutrition behaviours is an investment in adult health .................. 7 2.3 There is potential for correcting nutritional inadequacies and perhaps even for catch-up growth ....................................................................................................................... 8 2.4 Nutrition intervention in adolescent girls may contribute to breaking the vicious cycle of intergenerational malnutrition, poverty and chronic disease ................................. 9 2.5 Reaching households and communities through adolescents ............................................ 10 3. ADOLESCENCE IS A PERIOD OF NUTRITIONAL VULNERABILITY ..................................... 11 3.1 Conceptual framework for the analysis of nutritional problems in adolescence .............. 11 3.2 Nutritional problems in adolescence .................................................................................... 13 3.2.1 Undernutrition, stunting and consequences in adolescence ............................... 14 3.2.1.1 Overview on malnutrition in adolescence ............................................. 14 3.2.1.2 Malnutrition delays physical growth and maturation .......................... 16 3.2.1.3 Stunting and delayed maturation compound risk of adolescent pregnancy ................................................................................................. 16 3.2.1.4 Malnutrition reduces work capacity ...................................................... 16 3.2.2 Iron deficiency anaemia and other widespread micronutrient deficiencies ....... 17 3.2.2.1 Iron deficiency and anaemia ................................................................... 17 3.2.2.2 Vitamin A deficiency ............................................................................... 20 3.2.2.3 Iodine deficiency disorders ..................................................................... 20 3.2.2.4 Micronutrient deficiencies and bone disease ........................................ 20 3.2.3 Obesity and other nutrition-related chronic diseases .......................................... 22 3.2.3.1 Obesity ..................................................................................................... 22 3.2.3.2 Cardiovascular disease risks.................................................................... 24 3.2.3.3 Nutrition, gout and gallstones ................................................................ 25 3.2.3.4 Nutrition and cancer ............................................................................... 26 3.2.4 Tooth decay, a nutrition-related problem in adolescence .................................... 27 3.3 Early pregnancy, a well-documented factor of health and nutritional risk in adolescent girls.......................................................................................................................................... 27 3.3.1 Maternal mortality and morbidity ........................................................................ 28 3.3.2 Low birth weight and prematurity ........................................................................ 29 3.3.3 Lactational performance ........................................................................................ 29 3.3.4 Socioeconomic consequences and correlates........................................................ 30 3.4 Lifestyle and eating patterns, major threats to adolescents’ nutritional status .................. 31 3.4.1 Typical eating patterns and intakes of adolescents............................................... 31 3.4.2 Commercial, cultural and psychosocial influences on eating patterns ............... 32
3.4.3 Body image,obesity,dieting and eating disturbances........33 3.4.3.1 The concept of body image34 3.4.3.2 Body image and dieting practices...... 34 3.4.3.3 Eating disorders and disturbances ....... 35 3.4.4 Interrelationships of eating and other health-related lifestyle factors.35 3.4.5 Socioeconomic factors and risk of inadequate diets.37 3.4.5.1 Gender inequality 37 3.4.5.2 Poverty and lack of access to food (food insecurity)..... .37 4 STRATEGIES AND APPROACHES TO IMPROVE ADOLESCENTS'NUTRITION...................39 4.1 General strategies and intervention 4.1.1 Integration of health,nutrition and development of adolescents..... .39 4.1.2 Participation,but confidential health services,crucial in adolescents..............40 4.1.3 Life skills,health promotion and other intervention models for adolescents....41 4.2 Programmatic approaches targeting adolescents.43 4.2.1 School-based programmes 43 4.2.1.1 Overview of policies and programmes...............................43 4.2.1.2 Examples of effective school-based nutrition programmes ...............45 4.2.2 Child-to-child,youth groups,and other community-based programmes........48 4.3 Overall strategy for nutrition intervention in adolescence 49 4.4 Nutrition promotion,as part of health promotion......... 51 4.5 Prevention and management of nutritional disorders and risk conditions...................53 4.5.1 Nutritional assessment based on anthropometry and inquiry:Specific issues in adolescence53 4.5.1.1 Nutritional anthropometry. 54 4.5.1.2 Dietary inquiry... 56 4.5.2 Control of iron and other micronutrient deficiencies in adolescents................. 57 4.5.2.1 Iron deficiency and anaemia .57 4.5.2.2 Iodine deficiency. 58 4.5.2.3 Vitamin A deficiency 59 4.5.2.4 Other micronutrient inadequacies...... 60 4.5.2.5 Some comments on micronutrient strategies 60 4.5.3 Nutrition integration in antenatal (and postnatal)care for adolescents.............61 4.5.3.1 Is antenatal care nutritionally effective?. 62 4.5.3.2 Screening for risk factors........... .63 4.5.3.3 Initial anthropometric assessment and weight-gain monitoring.......63 4.5.3.4 Nutrition intervention. …64 4.5.4 Prevention and management of obesity67 4.5.5 Prevention of eating disturbances.. …69 4.5.6 Management of severe malnutrition in adolescents,particularly in emergency 4.6 Case management of nutritional problems in health care.......73 4.6.1 Adolescents with diabetes mellitus 73 4.6.2 Adolescents with HIV/AIDS5 4.6.3 Food allergies and intolerances8 4.6.3.1 Food allergies 78 4.6.3.2 Celiac disease 79 4.6.3.3 Lactose intolerance.............. .79 4.6.3.4 Other:hyperlipidemia;sickle cell anaemia 80 4.7 Synthesis:good practices for health-care providers to attend to the nutrition needs of adolescents.8 iv/
iv/ 3.4.3 Body image, obesity, dieting and eating disturbances.......................................... 33 3.4.3.1 The concept of body image ..................................................................... 34 3.4.3.2 Body image and dieting practices........................................................... 34 3.4.3.3 Eating disorders and disturbances ......................................................... 35 3.4.4 Interrelationships of eating and other health-related lifestyle factors ................ 35 3.4.5 Socioeconomic factors and risk of inadequate diets ............................................ 37 3.4.5.1 Gender inequality .................................................................................... 37 3.4.5.2 Poverty and lack of access to food (food insecurity) ............................ 37 4 STRATEGIES AND APPROACHES TO IMPROVE ADOLESCENTS’ NUTRITION .................. 39 4.1 General strategies and intervention models......................................................................... 39 4.1.1 Integration of health, nutrition and development of adolescents ...................... 39 4.1.2 Participation, but confidential health services, crucial in adolescents ................ 40 4.1.3 Life skills, health promotion and other intervention models for adolescents .... 41 4.2 Programmatic approaches targeting adolescents................................................................. 43 4.2.1 School-based programmes..................................................................................... 43 4.2.1.1 Overview of policies and programmes .................................................. 43 4.2.1.2 Examples of effective school-based nutrition programmes ................. 45 4.2.2 Child-to-child, youth groups, and other community-based programmes ......... 48 4.3 Overall strategy for nutrition intervention in adolescence ................................................. 49 4.4 Nutrition promotion, as part of health promotion ............................................................. 51 4.5 Prevention and management of nutritional disorders and risk conditions....................... 53 4.5.1 Nutritional assessment based on anthropometry and inquiry: Specific issues in adolescence ......................................................................................................... 53 4.5.1.1 Nutritional anthropometry .................................................................... 54 4.5.1.2 Dietary inquiry ........................................................................................ 56 4.5.2 Control of iron and other micronutrient deficiencies in adolescents................. 57 4.5.2.1 Iron deficiency and anaemia ................................................................... 57 4.5.2.2 Iodine deficiency ..................................................................................... 58 4.5.2.3 Vitamin A deficiency ............................................................................... 59 4.5.2.4 Other micronutrient inadequacies......................................................... 60 4.5.2.5 Some comments on micronutrient strategies ....................................... 60 4.5.3 Nutrition integration in antenatal (and postnatal) care for adolescents ............ 61 4.5.3.1 Is antenatal care nutritionally effective?................................................. 62 4.5.3.2 Screening for risk factors ........................................................................ 63 4.5.3.3 Initial anthropometric assessment and weight-gain monitoring ........ 63 4.5.3.4 Nutrition intervention ............................................................................ 64 4.5.4 Prevention and management of obesity................................................................ 67 4.5.5 Prevention of eating disturbances ......................................................................... 69 4.5.6 Management of severe malnutrition in adolescents, particularly in emergency situations .............................................................................................. 72 4.6 Case management of nutritional problems in health care .................................................. 73 4.6.1 Adolescents with diabetes mellitus ........................................................................ 73 4.6.2 Adolescents with HIV/AIDS .................................................................................. 75 4.6.3 Food allergies and intolerances .............................................................................. 78 4.6.3.1 Food allergies ........................................................................................... 78 4.6.3.2 Celiac disease ........................................................................................... 79 4.6.3.3 Lactose intolerance .................................................................................. 79 4.6.3.4 Other: hyperlipidemia; sickle cell anaemia ............................................ 80 4.7 Synthesis: good practices for health-care providers to attend to the nutrition needs of adolescents .............................................................................................................................. 80
5 CONCLUSIONS AND RECOMMENDATIONS..83 5.1 Adolescents are vulnerable and deserve special attention in nutrition........83 5.2 Need for inclusive strategies and specific policies for adolescent nutrition at country 5.3 Evidence-based strategic orientations ........ .89 5.3.1 Caveat on'evidence-based'decision-making and planning .......89 5.3.2 Primary focus on nutrition promotion,the key role of schools,and the importance of dietary guidelines.90 5.3.3 Adolescent girls as a priority target group,before the first pregnancy.....91 5.3.4 More of an integrated and food-based approach to micronutrient IhalnutFitiODl92 5.3.5 The importance of preventing obesity (and eating disturbances)..93 5.4 Reseatch needs94 5.4.1 On eating behaviours and determinants in adolescents:.94 5.4.2 On nutritional status94 5.4.3 On effectiveness of interventions.95 5.5 Recommendations to WHO for priority action and research........95 5.5.1 Technical Support.95 5.5.2 Research priorities ..... .96 REFERENCES.... 4100 FIGURES 1. Conceptual framework of nutritional problems and causal factors in adolescence........12 2. Overall strategy for nutrition intervention in adolescence5.0 3. A model of eating and weight-related behaviour ......................70 CHARTS 1. Nutrition of adolescents:Good practices for health care providers..81 2. Nutrition intervention:Dealing with adolescents............. .84 APPENDICES: I Nutritional status of adolescents in developing countries.97 0 Selected percentiles of waist circumferences by race,sex,and age......99 NUTRIT I ON IN A DO L E SC E N C E /v
N U T R I T I O N I N A D O L E S C E N C E / v 5 CONCLUSIONS AND RECOMMENDATIONS ............................................................................ 83 5.1 Adolescents are vulnerable and deserve special attention in nutrition .............................. 83 5.2 Need for inclusive strategies and specific policies for adolescent nutrition at country level ......................................................................................................................................... 89 5.3 Evidence-based strategic orientations .................................................................................. 89 5.3.1 Caveat on ‘evidence-based’ decision-making and planning ................................ 89 5.3.2 Primary focus on nutrition promotion, the key role of schools, and the importance of dietary guidelines........................................................................... 90 5.3.3 Adolescent girls as a priority target group, before the first pregnancy ............... 91 5.3.4 More of an integrated and food-based approach to micronutrient malnutrition ............................................................................................................ 92 5.3.5 The importance of preventing obesity (and eating disturbances) ...................... 93 5.4 Research needs........................................................................................................................ 94 5.4.1 On eating behaviours and determinants in adolescents: ..................................... 94 5.4.2 On nutritional status .............................................................................................. 94 5.4.3 On effectiveness of interventions .......................................................................... 95 5.5 Recommendations to WHO for priority action and research ............................................ 95 5.5.1 Technical support ................................................................................................... 95 5.5.2 Research priorities .................................................................................................. 96 REFERENCES........................................................................................................................................... 100 FIGURES 1. Conceptual framework of nutritional problems and causal factors in adolescence ......... 12 2. Overall strategy for nutrition intervention in adolescence ................................................. 50 3. A model of eating and weight-related behaviour ................................................................ 70 CHARTS 1. Nutrition of adolescents: Good practices for health care providers ................................... 81 2. Nutrition intervention: Dealing with adolescents ............................................................... 84 APPENDICES: I Nutritional status of adolescents in developing countries .................................................. 97 II. Selected percentiles of waist circumferences by race, sex, and age ..................................... 99
Acknowledgements The World Health Organization(WHO)would like to thank author of this paper,Dr Helene Delisle, Professor,Department of Nutrition,Faculty of Medicine,University of Montreal,Canada. Special thanks also go to Dr B.De Benoist of the WHO Department of Nutrition for Health and Development (NHD)for his valuable contributions to the revision and finalization of the paper,and Ms D.Klinger of the Department of Child and Adolescent Health and Development(CAH)for editing it.Many thanks also go to the WHO regional advisors on adolescent health and development from WHO AFRO,AMRO,EMRO,EURO,SEARO,and WPRO regional offices. Acknowledgement is also made of the contributions of(in alphabetical order):Dr A.Pradilla,Universidad del Valle,Colombia;Dr J.Rivera-Dommarco,Instituto Nacional de Salud Publica,Mexico;Dr R.Solon, Nutrition Center of the Philippines,Philippines;and Dr.R.Uauy,Instituto de Nutricion y Technologicas de la Alimentos,Chile,who acted as external reviewers.Acknowledgement is also made of the coordinating roles played by Dr V.Chandra-Mouli,Ms J.Ferguson,and Dr A.Olukoya of CAH. vi/
vi/ Acknowledgements The World Health Organization (WHO) would like to thank author of this paper, Dr Hélène Delisle, Professor, Department of Nutrition, Faculty of Medicine, University of Montreal, Canada. Special thanks also go to Dr B. De Benoist of the WHO Department of Nutrition for Health and Development (NHD) for his valuable contributions to the revision and finalization of the paper, and Ms D. Klinger of the Department of Child and Adolescent Health and Development (CAH) for editing it. Many thanks also go to the WHO regional advisors on adolescent health and development from WHO AFRO, AMRO, EMRO, EURO, SEARO, and WPRO regional offices. Acknowledgement is also made of the contributions of (in alphabetical order): Dr A. Pradilla, Universidad del Valle, Colombia; Dr J. Rivera-Dommarco, Instituto Nacional de Salud Publica, Mexico; Dr R. Solon, Nutrition Center of the Philippines, Philippines; and Dr. R. Uauy, Instituto de Nutricion y Technologicas de la Alimentos, Chile, who acted as external reviewers. Acknowledgement is also made of the coordinating roles played by Dr V. Chandra-Mouli, Ms J. Ferguson, and Dr A. Olukoya of CAH
Preface The overall purpose of this document is to present the factors and current thinking which underlie WHO's recommendations for the prevention of nutritional disorders in adolescents,and for their early detection,diagnosis and appropriate management.Following a brief Introduction(PART 1)to the particular features of adolescence and to the opportunities it provides,the three specific objectives of the document are dealt with as follows: PART 2-to identify the key nutritional problems that affect adolescents,the main risk factors, and their interaction with other health problems and life events PART 3-to identify and discuss existing recommendations,strategies and programmes on the prevention and control of these conditions PART4-to propose a number of more specific actions for the health sector to address the nutrition- related needs of adolescents in the light of scientific evidence and lessons learned,while insisting on the importance of intersectoral approaches to nutrition in consideration of the multifactorial etiology of nutrition problems. The focus throughout this document is on adolescents in developing countries,and this means addressing nutritional problems that are common to high,middle,and low-income groups,as well as those that are spreading throughout the world as a result of globalization.Although much of the research into the various factors of nutritional risk in adolescents has been carried out in high-income countries,many of the findings are also of relevance to middle and low-income settings. Nevertheless,because of the very wide differences which exist between(and even within)all countries, the generalizing of problems or solutions is often meaningless.Although developed and developing country categories are used for the sake of simplicity,this dichotomy is becoming more and more irrelevant with respect to nutritional problems or other issues.The current document therefore deals where possible with adolescent nutritional issues in the context of the relevant setting. Public health nutrition is given more emphasis than clinical nutrition since promotion and prevention are deemed more critical to adolescent nutritional health than individual case management,and because the recommendations are primarily intended for health-care providers and not for clinical nutritionists or dietitians.This paper does not therefore discuss in detail the nutritional requirements and dietary allowances of adolescents,nor does it delve into specific clinical conditions requiring therapeutic diets. It is felt that these aspects are beyond the scope of the present work.Furthermore,as it is becoming increasingly difficult to exhaustively cover all nutritional disorders,deficiencies,and risks in a single work,consideration has been focused upon a number of higher priority areas. Adolescents are tomorrow's adult population,and their health and well-being are crucial.Yet,interest in the health of adolescents is relatively recent,and a focus on nutrition is even more recent,with the exception of adolescent pregnancy.This discussion paper intends to make evidence-based recommendations to help improve the contribution made by health-care providers to the nutritional health of adolescents,particularly in developing countries. N UT RIT I O N I N A D O L E S C E N C E vii
N U T R I T I O N I N A D O L E S C E N C E / vii Preface The overall purpose of this document is to present the factors and current thinking which underlie WHO’s recommendations for the prevention of nutritional disorders in adolescents, and for their early detection, diagnosis and appropriate management. Following a brief Introduction (PART 1) to the particular features of adolescence and to the opportunities it provides, the three specific objectives of the document are dealt with as follows: • PART 2 – to identify the key nutritional problems that affect adolescents, the main risk factors, and their interaction with other health problems and life events • PART 3– to identify and discuss existing recommendations, strategies and programmes on the prevention and control of these conditions • PART 4 – to propose a number of more specific actions for the health sector to address the nutritionrelated needs of adolescents in the light of scientific evidence and lessons learned, while insisting on the importance of intersectoral approaches to nutrition in consideration of the multifactorial etiology of nutrition problems. The focus throughout this document is on adolescents in developing countries, and this means addressing nutritional problems that are common to high, middle, and low-income groups, as well as those that are spreading throughout the world as a result of globalization. Although much of the research into the various factors of nutritional risk in adolescents has been carried out in high-income countries, many of the findings are also of relevance to middle and low-income settings. Nevertheless, because of the very wide differences which exist between (and even within) all countries, the generalizing of problems or solutions is often meaningless. Although developed and developing country categories are used for the sake of simplicity, this dichotomy is becoming more and more irrelevant with respect to nutritional problems or other issues. The current document therefore deals where possible with adolescent nutritional issues in the context of the relevant setting. Public health nutrition is given more emphasis than clinical nutrition since promotion and prevention are deemed more critical to adolescent nutritional health than individual case management, and because the recommendations are primarily intended for health-care providers and not for clinical nutritionists or dietitians. This paper does not therefore discuss in detail the nutritional requirements and dietary allowances of adolescents, nor does it delve into specific clinical conditions requiring therapeutic diets. It is felt that these aspects are beyond the scope of the present work. Furthermore, as it is becoming increasingly difficult to exhaustively cover all nutritional disorders, deficiencies, and risks in a single work, consideration has been focused upon a number of higher priority areas. Adolescents are tomorrow’s adult population, and their health and well-being are crucial. Yet, interest in the health of adolescents is relatively recent, and a focus on nutrition is even more recent, with the exception of adolescent pregnancy. This discussion paper intends to make evidence-based recommendations to help improve the contribution made by health-care providers to the nutritional health of adolescents, particularly in developing countries
1 INTRODUCTION Adolescents are tomorrow's adult population and their health and well-being are crucial.Yet.interest in adolescents'health is relatively recent and a focus on nutrition is even more recent,with the exception of adolescent pregnancy.This discussion paper intends to make evidence-based recommendations directed at the health sector to improve the contribution of health-care providers to nutritional health of adolescents,particularly in developing countries. 1.1 Adolescents:Who are they? The term youth encompasses ages 10 to 24 years,while the term adolescents as defined by WHO(1986a) includes persons aged 10-19.Adolescents are sometimes designated as'children,for instance,in the UN Convention on the Rights of the Child of 1989,which applies to all individuals below 18 years of age. The period of gradual transition from childhood to adulthood that normally begins with the onset of signs of puberty,is characterized by important psychological and social changes,not only physiological change.It is difficult to define in universal terms for there are important cultural differences.Depending on societies,the transition may be quick and the very notion of adolescence does not really exist,for instance where girls marry early and do not go to school.On the other hand,the transition of adolescence may extend over several years where young people remain in school and marry late,like in developed countries and increasingly in urban areas of developing countries(Paxman and Zuckerman,1987). Adolescents are far from being a homogeneous group,in terms of development,maturity and lifestyle. Even for a given place and age,there is a great deal of diversity depending on personal and environmental factors.Adolescence may be divided into three developmental stages based on physical,psychological and social changes(WHO/UNICEF 1995): Early adolescence,10/13-14/15 years; Mid adolescence,14/15-17; Late adolescence,between 17-21,but variable. Being in transition,adolescents may no longer benefit from the attention and care that usually go to children,but they may not get the protections associated with adulthood either. Adolescents make up roughly 20%of the total world population.In developing countries,adolescents have an even higher demographic weight,for instance,roughly 26%in Salvador,compared to 14%in USA(Burt 1996).Similarly,in the Philippines,it is estimated that adolescents represent one quarter of the total population(Bouis et al,1998).In 1995,there were914 million adolescents living in the developing world,that is,85%of the total(United Nations 1997).Their number is expected to reach 1.13 billion by the year 2025.With a lower fertility decline,Africa is expected to see its adolescent population grow much more rapidly than Asia and Latin America. Adolescence is a period of rapid growth:up to 45%of skeletal growth takes place and 15 to 25%of adult height is achieved during adolescence(Rees and Christine,1989).During the growth spurt of adolescence, up to 37%of total bone mass may be accumulated(Key and Key,1994).Nutrition influences growth and development throughout infancy,childhood and adolescence;it is,however,during the period of adolescence that nutrient needs are the greatest(Lifshitz,Tarim and Smith,1993). Psychological and social aspects of adolescents'development are less often described in connection with adolescent health than their physical growth and maturation characteristics(Gillespie 1997).And yet NUTRITION IN A DO LESCE N CE /1
NUTRITION IN ADOLESCENCE / 1 1 INTRODUCTION Adolescents are tomorrow’s adult population and their health and well-being are crucial. Yet, interest in adolescents’ health is relatively recent and a focus on nutrition is even more recent, with the exception of adolescent pregnancy. This discussion paper intends to make evidence-based recommendations directed at the health sector to improve the contribution of health-care providers to nutritional health of adolescents, particularly in developing countries. 1.1 Adolescents: Who are they? The term youth encompasses ages 10 to 24 years, while the term adolescents as defined by WHO (1986a) includes persons aged 10-19. Adolescents are sometimes designated as ‘children’, for instance, in the UN Convention on the Rights of the Child of 1989, which applies to all individuals below 18 years of age. The period of gradual transition from childhood to adulthood that normally begins with the onset of signs of puberty, is characterized by important psychological and social changes, not only physiological change. It is difficult to define in universal terms for there are important cultural differences. Depending on societies, the transition may be quick and the very notion of adolescence does not really exist, for instance where girls marry early and do not go to school. On the other hand, the transition of adolescence may extend over several years where young people remain in school and marry late, like in developed countries and increasingly in urban areas of developing countries (Paxman and Zuckerman, 1987). Adolescents are far from being a homogeneous group, in terms of development, maturity and lifestyle. Even for a given place and age, there is a great deal of diversity depending on personal and environmental factors. Adolescence may be divided into three developmental stages based on physical, psychological and social changes (WHO/UNICEF 1995): • Early adolescence, 10/13-14/15 years; • Mid adolescence, 14/15-17; • Late adolescence, between 17-21, but variable. Being in transition, adolescents may no longer benefit from the attention and care that usually go to children, but they may not get the protections associated with adulthood either. Adolescents make up roughly 20% of the total world population. In developing countries, adolescents have an even higher demographic weight, for instance, roughly 26% in Salvador, compared to 14% in USA (Burt 1996). Similarly, in the Philippines, it is estimated that adolescents represent one quarter of the total population (Bouis et al, 1998). In 1995, there were 914 million adolescents living in the developing world, that is, 85% of the total (United Nations 1997). Their number is expected to reach 1.13 billion by the year 2025. With a lower fertility decline, Africa is expected to see its adolescent population grow much more rapidly than Asia and Latin America. Adolescence is a period of rapid growth: up to 45% of skeletal growth takes place and 15 to 25% of adult height is achieved during adolescence (Rees and Christine, 1989). During the growth spurt of adolescence, up to 37% of total bone mass may be accumulated (Key and Key, 1994). Nutrition influences growth and development throughout infancy, childhood and adolescence; it is, however, during the period of adolescence that nutrient needs are the greatest (Lifshitz, Tarim and Smith, 1993). Psychological and social aspects of adolescents’ development are less often described in connection with adolescent health than their physical growth and maturation characteristics (Gillespie 1997). And yet
the former are as relevant to health and nutrition as the latter.Although the old stereotypes of 'generation gaps'and'identity crises'need to be revisited,adolescence nonetheless operates a transition towards greater autonomy from parents and their values,and a progressively more central role of peers as role models,advisors,friends,and determinants of interests and values(Shepherd and Dennison,1996; Mays and Orr,1996).A now-dominant thinking is that most adolescents negotiate this transition without major disruptions or high risk behaviours,strengthening their own identity while maintaining their relationships with parents,and building new extra-familial relationships and skills(Offer 1987).Based on a review of international surveys of youth for the Lisbon Conference of 1998,Richard and Braungart! support this view,and contend that young people in general do not regard themselves as alienated, rebellious or antagonistic towards their families and adults.The majority of young people express positive views about themselves and their life situation,although a growing number do admit to some risky, experimental behaviours.Only a minority are involved in serious problems such as drug abuse,gangs and crime,and teenage pregnancy.They express the need for opportunities to develop a sense of independence,competence and participation in society.It is interesting that the 1996 study on 25,000 middle-class high-school students aged 15-18 years on five continents found them to be more similar than different in their values and concerns.According to this report',growing up in a developed or advanced nation today does not mean that youth problems are minimized.A gender gap seems to exist irrespective of the setting,in that boys express greater self-confidence,less vulnerability,and more happiness,pride and a subjective sense of well-being than girls.Conversely,adolescent girls have a higher self and body awareness than boys,and they tend to be less satisfied not only with their body,but also their appearance,their health,their personality (Cordonnier 1995).While young girls from western nations are more exposed to problems such as eating disorders,young women from developing countries are apparently at higher risk for suicide.A majority of adolescents think they are in good health,and they tend to feel invulnerable,with little motivation to protect their health"capital"for the future.This has a direct bearing on health promotion strategies. 1.2 Increasing focus on adolescent health and well-being The sheer number and demographic weight of youth(or adolescents)gives them importance,even more so in developing countries,with a typically younger population,and as a result of the drop in under-five mortality.The future economic development of poorer countries rests in large part on the prospect of having increasing proportions of the future adults who are educated,healthy and economically productive.There is an important interaction between economic opportunity and attitudes of the youth as pertinently noted by Burt (1996).If there is little realistic hope of getting ahead economically, adolescents may have little incentive to invest in education and to stay away from health-threatening activities or behaviours.Conversely,without the prospect of a qualified,healthy and productive workforce, potential investors may be reluctant to commit to economic development.There are substantial costs to governments,societies and individuals for every failure of youth to reach adulthood alive,healthy,well educated and without dependants for whom they cannot care.When advocating investment in adolescents,it is important to consider specific cultural values,and to identify the most valued as well as the least wanted personal and societal outcomes. The UNICEF Executive Director stated in a keynote address2 that adolescents hold the key to the 21" century,insisting on the remarkable extent to which participating adolescents are a positive force for needed social change: "There are one billion adolescents world-wide,and how effectively they cope with the perils of growing up will be a crucial element in whether humanity can surmount the challenge of the next Century. Assuring young people's right to health and development is central to preventing immediate threats and a host of later problems that can threaten not only their lives,but their children's" Web site:www.un.org/events/youth98/backinfo/yreport.html,18/04/99 2 Web site:www.uniceforg/newsline/99pr6.htm,16/04/99
2/ 1 Web site: www.un.org/events/youth98/backinfo/yreport.html, 18/04/99 2 Web site: www.unicef.org/newsline/99pr6.htm, 16/04/99 the former are as relevant to health and nutrition as the latter. Although the old stereotypes of ‘generation gaps’ and ‘identity crises’ need to be revisited, adolescence nonetheless operates a transition towards greater autonomy from parents and their values, and a progressively more central role of peers as role models, advisors, friends, and determinants of interests and values (Shepherd and Dennison, 1996; Mays and Orr, 1996). A now-dominant thinking is that most adolescents negotiate this transition without major disruptions or high risk behaviours, strengthening their own identity while maintaining their relationships with parents, and building new extra-familial relationships and skills (Offer 1987). Based on a review of international surveys of youth for the Lisbon Conference of 1998, Richard and Braungart1 support this view, and contend that young people in general do not regard themselves as alienated, rebellious or antagonistic towards their families and adults. The majority of young people express positive views about themselves and their life situation, although a growing number do admit to some risky, experimental behaviours. Only a minority are involved in serious problems such as drug abuse, gangs and crime, and teenage pregnancy. They express the need for opportunities to develop a sense of independence, competence and participation in society. It is interesting that the 1996 study on 25,000 middle-class high-school students aged 15-18 years on five continents found them to be more similar than different in their values and concerns. According to this report1 , growing up in a developed or advanced nation today does not mean that youth problems are minimized. A gender gap seems to exist irrespective of the setting, in that boys express greater self-confidence, less vulnerability, and more happiness, pride and a subjective sense of well-being than girls. Conversely, adolescent girls have a higher self and body awareness than boys, and they tend to be less satisfied not only with their body, but also their appearance, their health, their personality (Cordonnier 1995). While young girls from western nations are more exposed to problems such as eating disorders, young women from developing countries are apparently at higher risk for suicide. A majority of adolescents think they are in good health, and they tend to feel invulnerable, with little motivation to protect their health “capital” for the future. This has a direct bearing on health promotion strategies. 1.2 Increasing focus on adolescent health and well-being The sheer number and demographic weight of youth (or adolescents) gives them importance, even more so in developing countries, with a typically younger population, and as a result of the drop in under-five mortality. The future economic development of poorer countries rests in large part on the prospect of having increasing proportions of the future adults who are educated, healthy and economically productive. There is an important interaction between economic opportunity and attitudes of the youth as pertinently noted by Burt (1996). If there is little realistic hope of getting ahead economically, adolescents may have little incentive to invest in education and to stay away from health-threatening activities or behaviours. Conversely, without the prospect of a qualified, healthy and productive workforce, potential investors may be reluctant to commit to economic development. There are substantial costs to governments, societies and individuals for every failure of youth to reach adulthood alive, healthy, well educated and without dependants for whom they cannot care. When advocating investment in adolescents, it is important to consider specific cultural values, and to identify the most valued as well as the least wanted personal and societal outcomes. The UNICEF Executive Director stated in a keynote address2 that adolescents hold the key to the 21st century, insisting on the remarkable extent to which participating adolescents are a positive force for needed social change: “There are one billion adolescents world-wide, and how effectively they cope with the perils of growing up will be a crucial element in whether humanity can surmount the challenge of the next Century. [...] Assuring young people’s right to health and development is central to preventing immediate threats and a host of later problems that can threaten not only their lives, but their children’s
For a number of years,the health of adolescents has not been a major concern and research has consequently been limited,as they are less susceptible to disease and suffer from fewer life-threatening conditions than children and elderly people.Indeed,adolescence is generally described as a period of relatively good health with low prevalence of infection and chronic disease(Senderowitz 1995).Mortality and morbidity trends among adolescents are quite similar in developing and developed countries(Blum 1991;Maddaleno and Silber,1993).It is noteworthy that health services in developing countries focus on preschool-age children and pregnant women,with the consequence that health needs of adolescents may not be adequately met. However,adolescents are very vulnerable to major social and economic changes,with resulting behaviours that threaten health,including:increased and unprotected sexual activity;substance use;and propensity to risk-taking.The costs and effects develop over a lifetime(Burt 1996).Reproductive health is understandably a major concern,with the human immunodeficiency virus(HIV),other sexually transmitted diseases(STD)and early pregnancy as main issues.One third of new STD cases,more than half the new HIV infections and one third of all births are among youth.While the five leading causes of death,illness and disability among young men are depression,traffic accidents,alcohol use,war and schizophrenia,in young women they are depression,obstructed labour,suicide,chlamydia and iron- deficiency anaemia' Since the International Youth Year of 1985 with its focus on participation,development and peace, world interest in adolescent issues in general and in the area of health in particular,has grown dramatically, as reflected in official policies and programmes.The United Nations General Assembly adopted in 1995 an international strategy:the World Programme of Action for Youth in the year 2000 and beyond3. Within the United Nations system,the Youth Unit has been set up as the focal point on matters relating to youth'.The World Programme recognizes that the situation of youths worldwide remains precarious and that,both in developed and developing countries,needs and aspirations of young people are still largely unmet.It is intended to address more effectively the problems of young people and to increase opportunities for their participation in society.Retaining the three themes of the International Youth Year,it identifies ten priority areas for action aimed at improving the situation and well-being of young people:education,employment,hunger and poverty,health,environment,drug abuse,juvenile delinquency,leisure time activities,girls and young women,and participation of youths in the life of society and in decision making,which cuts across the other issues3.Under health priorities,actions that are relevant for nutrition are not only nutrition education,but also preventive health programmes,the promotion of healthier lifestyles in cooperation with youth organizations,programmes to ensure universal and non-discriminatory access to primary health care,and school programmes of health knowledge and practices.Food security,a major determinant of nutritional health,is also addressed under the hunger and poverty'priority area. The First World Conference of Ministers responsible for youth was held in Lisbon in August 1998 and the Lisbon Declaration on Youth,Policies and Programmes was adopted.It focuses on national youth policy development and implementation,enhanced participation of youth,action for education, development,peace,health and prevention of drug and substance abuse.The only health commitment directly addressing nutrition consists of improving access to malnutrition-prevention programmes as part of basic health care.The Braga Youth Action Plan was later adopted by the Third World Youth Forum of the United Nations held in Braga(Portugal),also in 1998.Recommendations are under youth policies and participation.Those that are of more direct relevance to health and nutrition are:that national youth policies,coupled with action plans,be cross-sectoral,comprehensive and formulated with long-term vision;and that integrated national youth health policy be formulated/reviewed and implemented,to address all major issues,including sexual and reproductive health,nutrition and hygiene, with the active participation of youth and youth-related organizations 3 Web site:www.un.org/events/youth98/backinfo/yreport.htm,18/04/99 Web site:www.un.org/esa/socdev/unyin,18/04/99 Web site:see footnote 4 NUTRITION IN A DO LES C E N C E /3
NUTRITION IN ADOLESCENCE / 3 3 Web site: www.un.org/events/youth98/backinfo/yreport.htm, 18/04/99 4 Web site: www.un.org/esa/socdev/unyin, 18/04/99 5 Web site: see footnote 4 For a number of years, the health of adolescents has not been a major concern and research has consequently been limited, as they are less susceptible to disease and suffer from fewer life-threatening conditions than children and elderly people. Indeed, adolescence is generally described as a period of relatively good health with low prevalence of infection and chronic disease (Senderowitz 1995). Mortality and morbidity trends among adolescents are quite similar in developing and developed countries (Blum 1991; Maddaleno and Silber, 1993). It is noteworthy that health services in developing countries focus on preschool-age children and pregnant women, with the consequence that health needs of adolescents may not be adequately met. However, adolescents are very vulnerable to major social and economic changes, with resulting behaviours that threaten health, including: increased and unprotected sexual activity; substance use; and propensity to risk-taking. The costs and effects develop over a lifetime (Burt 1996). Reproductive health is understandably a major concern, with the human immunodeficiency virus (HIV), other sexually transmitted diseases (STD) and early pregnancy as main issues. One third of new STD cases, more than half the new HIV infections and one third of all births are among youth. While the five leading causes of death, illness and disability among young men are depression, traffic accidents, alcohol use, war and schizophrenia, in young women they are depression, obstructed labour, suicide, chlamydia and irondeficiency anaemia3 . Since the International Youth Year of 1985 with its focus on participation, development and peace, world interest in adolescent issues in general and in the area of health in particular, has grown dramatically, as reflected in official policies and programmes. The United Nations General Assembly adopted in 1995 an international strategy: the World Programme of Action for Youth in the year 2000 and beyond3 . Within the United Nations system, the Youth Unit has been set up as the focal point on matters relating to youth4 . The World Programme recognizes that the situation of youths worldwide remains precarious and that, both in developed and developing countries, needs and aspirations of young people are still largely unmet. It is intended to address more effectively the problems of young people and to increase opportunities for their participation in society. Retaining the three themes of the International Youth Year, it identifies ten priority areas for action aimed at improving the situation and well-being of young people: education, employment, hunger and poverty, health, environment, drug abuse, juvenile delinquency, leisure time activities, girls and young women, and participation of youths in the life of society and in decision making, which cuts across the other issues5 . Under health priorities, actions that are relevant for nutrition are not only nutrition education, but also preventive health programmes, the promotion of healthier lifestyles in cooperation with youth organizations, programmes to ensure universal and non-discriminatory access to primary health care, and school programmes of health knowledge and practices. Food security, a major determinant of nutritional health, is also addressed under the ‘hunger and poverty’ priority area. The First World Conference of Ministers responsible for youth was held in Lisbon in August 1998 and the Lisbon Declaration on Youth, Policies and Programmes was adopted. It focuses on national youth policy development and implementation, enhanced participation of youth, action for education, development, peace, health and prevention of drug and substance abuse. The only health commitment directly addressing nutrition consists of improving access to malnutrition-prevention programmes as part of basic health care. The Braga Youth Action Plan was later adopted by the Third World Youth Forum of the United Nations held in Braga (Portugal), also in 1998. Recommendations are under youth policies and participation. Those that are of more direct relevance to health and nutrition are: that national youth policies, coupled with action plans, be cross-sectoral, comprehensive and formulated with long-term vision; and that integrated national youth health policy be formulated/reviewed and implemented, to address all major issues, including sexual and reproductive health, nutrition and hygiene, with the active participation of youth and youth-related organizations
Regarding health more specifically,a common agenda was developed by WHO,UNFPA and UNICEF (WHO 1997a;1999a)regarding actions for the health of adolescents,with the focus on improving knowledge,skills,access to counselling and health services,and safety and support of the environment (see Chapter 4).In'Health21:The Health for all Policy Framework for the WHO European Region,as revised in 1998,one of the two main aims is to promote and protect people's health throughout their lives,the other one being to reduce the incidence of the main diseases and injuries,and to alleviate the suffering they cause.Health as a fundamental human right,equity in health and solidarity in action,and participation and accountability for continued health development are the basic values(Health21 1998). PAHO has a Program of Adolescent Health(Division of Health Protection and Promotion)which seeks to promote the health and development of adolescents and youth between the ages of 10 and 24 in the Region,and which encompasses policy and advocacy,networking,evaluation of services and operational research. Blum(1998)has identified the key roles of the health sector for adolescent health in the USA,recognizing a more prominent role for public health than for personal health care-strategies and noting the relative scarcity of prevention programmes. It is noteworthy that in spite of a growing concern for adolescent health worldwide,adolescence has not been considered a high priority lifecycle stage for nutrition needs and intervention,with the exception of adolescent pregnancy.In the USA,however,nutrition was already outlined in 1990 as one of the key intervention areas in the'Healthier Youth by the Year 2000 Project'of the American Medical Association. It should be recalled that in the UN Convention on the Rights of the Child,which also applies to adolescents the need to "combat disease and malnutrition [through the provision of nutritious foods" in order to fulfil the right to the highest attainable standard of health is explicit in article 24. 1.3 Objectives and content of the paper Based on a literature search pertaining to developed and developing countries,the purpose of this discussion paper is to lay down the basis for WHO's recommendations on the prevention of nutritional disorders in adolescents and on their early detection/diagnosis and appropriate management.The specific objectives are: 1) to identify the key nutritional problems that affect adolescents,the main risk factors and their interaction with other health problems and life events; 2) to identify and discuss existing recommendations,strategies and programmes on prevention and control of these conditions;and 3) to propose additional recommendations when deemed relevant. The focus is on adolescents of developing countries,which means also addressing nutritional problems that are common to high-,middle-,and low-income groups,as well as those that are spreading throughout the world as a result of globalization.Much research on various factors of nutritional risk in adolescents has been carried out in high-income countries,with many findings also of relevance to middle-and low-income ones.Therefore,the discussion paper deals with adolescent nutritional issues and programmes within their own setting.An important caveat is that because of very wide differences that may exist between and even within countries,generalizing problems or solutions is irrelevant,and the paper may be perceived as being over-simplistic in this regard because of the need to synthesize.Although developed and developing country categories are used for the sake of simplicity,it is reaffirmed here that this distinction is becoming more and more irrelevant with respect to nutritional problems or other issues. Web site:www.paho.org/hpp/hppabout.htm,16/04/99
4/ 6 Web site: www.paho.org/hpp/hppabout.htm, 16/04/99 Regarding health more specifically, a common agenda was developed by WHO, UNFPA and UNICEF (WHO 1997a; 1999a) regarding actions for the health of adolescents, with the focus on improving knowledge, skills, access to counselling and health services, and safety and support of the environment (see Chapter 4). In ‘Health21: The Health for all Policy Framework for the WHO European Region’, as revised in 1998, one of the two main aims is to promote and protect people’s health throughout their lives, the other one being to reduce the incidence of the main diseases and injuries, and to alleviate the suffering they cause. Health as a fundamental human right, equity in health and solidarity in action, and participation and accountability for continued health development are the basic values (Health21 1998). PAHO has a Program of Adolescent Health (Division of Health Protection and Promotion) which seeks to promote the health and development of adolescents and youth between the ages of 10 and 24 in the Region6 , and which encompasses policy and advocacy, networking, evaluation of services and operational research. Blum (1998) has identified the key roles of the health sector for adolescent health in the USA, recognizing a more prominent role for public health than for personal health care-strategies and noting the relative scarcity of prevention programmes. It is noteworthy that in spite of a growing concern for adolescent health worldwide, adolescence has not been considered a high priority lifecycle stage for nutrition needs and intervention, with the exception of adolescent pregnancy. In the USA, however, nutrition was already outlined in 1990 as one of the key intervention areas in the ‘Healthier Youth by the Year 2000 Project’ of the American Medical Association. It should be recalled that in the UN Convention on the Rights of the Child, which also applies to adolescents the need to “combat disease and malnutrition [....] through the provision of nutritious foods” in order to fulfil the right to the highest attainable standard of health is explicit in article 24. 1.3 Objectives and content of the paper Based on a literature search pertaining to developed and developing countries, the purpose of this discussion paper is to lay down the basis for WHO’s recommendations on the prevention of nutritional disorders in adolescents and on their early detection/diagnosis and appropriate management. The specific objectives are: 1) to identify the key nutritional problems that affect adolescents, the main risk factors and their interaction with other health problems and life events; 2) to identify and discuss existing recommendations, strategies and programmes on prevention and control of these conditions; and 3) to propose additional recommendations when deemed relevant. The focus is on adolescents of developing countries, which means also addressing nutritional problems that are common to high-, middle-, and low-income groups, as well as those that are spreading throughout the world as a result of globalization. Much research on various factors of nutritional risk in adolescents has been carried out in high-income countries, with many findings also of relevance to middle- and low-income ones. Therefore, the discussion paper deals with adolescent nutritional issues and programmes within their own setting. An important caveat is that because of very wide differences that may exist between and even within countries, generalizing problems or solutions is irrelevant, and the paper may be perceived as being over-simplistic in this regard because of the need to synthesize. Although developed and developing country categories are used for the sake of simplicity, it is reaffirmed here that this distinction is becoming more and more irrelevant with respect to nutritional problems or other issues
