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Child and Adolescent Obesity: Causes, Consequences, Prevention and Management
BOOK REVIEWS
censorship. There is nothing voyeuristic about these photographs, but there is nothing particularly interesting about them, either. Despite its flaws, Nothing to Hide is a rich source of frank personal accounts from people with mental illness; it may be most rewarding to readers with a recently diagnosed family member. Certain poignant interviews lie in its pages like gems, and the book’s tone is optimistic. Even the repetition, though it grows dull, hammers home the point that mental illness is just that: illness, not a character flaw. That is what this unwieldy book sets out to demonstrate, and a patient reader will find that in this it succeeds. Jennifer Blair, B.S. Yale University School of Medicine New Haven, CT Andre´s Martin, M.D., M.P.H. Yale Child Study Center New Haven, CT DOI: 10.1097/01.CHI.0000111372.22274.fa
Child and Adolescent Obesity: Causes, Consequences, Prevention and Management. By Walter Burniat, Tim Cole, Inge Lissau, and Elizabeth Poskitt. Cambridge, England: Cambridge University Press, 2002, 416 pp., $90.00 (hardcover). It is evident that clear-cut solutions to the obesity epidemic do not abound. A book on childhood and adolescent obesity should provide a comprehensive review and point out new directions. This volume, edited by renowned European experts, partially fulfills this expectation. Guillaume and Lissau address the alarming secular trends worldwide. However, the problems inherent to the definition of obesity, well pointed out by Cole et al., seemingly preclude an international comparison. It remains to be seen whether the solution proposed by the International Obesity Task Force and advocated by the authors will catch on: because the BMI cutoff for childhood and adolescent obesity was obtained by averaging the curve passing through the adult cutoff of 30 kg/m2 at age 18, approximately 1% of the British population below age 18 is currently obese. Obviously, this markedly contrasts with the 20% prevalence rate in the adult British population. Thus, the reference to age 18 (and not to the whole adult age range) implies a very conservative estimate in minors; the dependency of prevalence rates on the respective cutoffs is evident. Obviously, a standard reference population is required for research purposes to enable international comparisons. More importantly, the
J. AM. ACAD. CHILD ADOLESC. PSYCHIATRY, 43:4, APRIL 2004
factors underlying differences in national prevalence rates need to be determined. The volume is curiously slanted away from the biological findings that have been at the center stage of recent obesity research. For example, only two pages pertain to monogenic obesity (in the chapter by Wabitsch; as in most other chapters, references go only through the year 2000). Moreover, the results of virtually hundreds of twin, adoption, and family studies on energy expenditure, including activity levels, dietary intake and taste preferences, are dealt with in only two paragraphs (Guillaume and Lissau), despite the fact that particularly high heritability estimates for BMI have been obtained in adolescents. The unmentioned fact that the shared environment seemingly contributes only little to BMI variance between relatives should have been subjected to a critical analysis of the implications for both environmental causation and treatment. Providing obese adolescents and their parents with detailed information on the genetic basis of their condition can have a profound impact by reducing feelings of guilt. Are the authors (or are we) perhaps afraid of providing this information, concerned that families will stop addressing the problem? If so, we urgently need studies to document the effects of educating families on the genetic basis of obesity. It seems that there is a deeply rooted fear of genetic determinism, which is all too readily associated with therapeutic nihilism. Admittedly an extremely rare condition, inborn leptin deficiency serves as an example of how the advent of molecular research has yielded a successful treatment approach. In that context, is it that unlikely that the 2% to 4% of extremely obese children with mutations in the melanocortin-4 receptor gene might one day be similarly amenable to pharmacological interventions? The ongoing unraveling of pathways underlying energy homeostasis might even provide us with pharmacological interventions for the majority of obese individuals, in whom a genetic predisposition cannot currently be elucidated at the molecular level. A direct discussion of the pros and cons of the potential implications of these recent developments is largely lacking in the volume. Only in Europe are extremely obese children and adolescents treated over weeks to months as inpatients (Frelut). In light of both the burden imposed on patients and their families, and of the considerable treatment costs involved, it is of the utmost importance to assess medium- and long-term outcomes: Childhood obesity is too serious a public health issue for the field to become complacent or satisfied with the results provided by studies with typical follow-up rates of less than 50%. Whereas the few studies available indicate that BMI is lower in individuals recontacted after treatment, we know nothing about the many ones lost to follow-up. The chapter by Frelut argues that even if all those lost to follow505
BOOK REVIEWS
up eventually regained their weight, the positive results obtained among those remaining in treatment would still render the entire treatment program successful. However, we should also be concerned not to do any harm: are we that sure that some of the adolescents lost to follow-up might not be somatically and/or psychologically harmed by a weight loss of 25 kg within 6 months, and by subsequently regaining their baseline weights? Randomized controlled studies are urgently required. Almost every university hospital specializing in eating disorders has performed a thorough follow-up study on anorexia nervosa patients, and follow-up rates typically exceed 85%. We thus have a solid notion of how these patients fare medically and psychosocially. This positive situation is in marked contrast to the lack of such studies for extremely obese children and adolescents. Are mortality rates higher than in anorexia nervosa? What percentage of obese adolescents enter the job market? How socially isolated do they become, and what somatic and psychiatric disorders do they develop at what age, and how do these affect their body weight? Apart from these scientific issues, we would benefit from a better understanding of the course of childhood obesity over time. Case reports and series, generally lacking from the book, would certainly help to bring this about. The editors are to be applauded for addressing prevention prior to management. This sequence is clearly trend-setting. Indeed, “no current program for the treatment of obesity is particularly successful” (pp. 243–269). Without giving up hope that better treatment modalities might evolve in the future via new pharmacological developments, we need to shift much more from conventional treatments to prevention. The magnitude of the problem warrants continuation of the traditional biomedical approach, while at the same time implementing new preventive strategies. At the popu-
506
lation level, even small reductions in mean body weight are likely to have a substantial impact on obesity-related morbidity and mortality. We need to learn to appreciate this large effect at the population level. To achieve such changes, a truly interdisciplinary approach will be required. What can we do to get teachers, sociologists, media experts, and economists more interested in childhood obesity and devise creative new approaches? Finally, and as rightly pointed out in the last chapter, “The Future” (by James), we have to deal with the fact that “some components of the food industry are brilliantly organized in their political lobbying and marketing schemes.” As therapists we should not give up the fight when confronted with this aspect: too much is at stake. Professions involved in the treatment of obesity must make themselves heard at the political level. We need to convince our leadership that the obesity epidemic cannot be solved on an individual basis. Instead, political action is required to ensure that children and adolescents become more physically active and that healthy eating habits are established. Creativity and public pressure will be required to provide the food industry with incentives to reduce the exposure among children and adults to unhealthy food. If this approach fails, appropriate legislation may become necessary. Johannes Hebebrand, M.D. Clinical Research Group Department of Child and Adolescent Psychiatry Philipps University Marburg, Germany DOI: 10.1097/01.CHI.0000111373.22274.b3
Note to publishers: Books for review should be sent to Andre´s Martin, M.D., M.P.H., Yale Child Study Center, 230 South Frontage Road, P.O. Box 207900, New Haven, CT 06520-7900.
J. AM. ACAD. CHILD ADOLESC. PSYCHIATRY, 43:4, APRIL 2004
censorship. There is nothing voyeuristic about these photographs, but there is nothing particularly interesting about them, either. Despite its flaws, Nothing to Hide is a rich source of frank personal accounts from people with mental illness; it may be most rewarding to readers with a recently diagnosed family member. Certain poignant interviews lie in its pages like gems, and the book’s tone is optimistic. Even the repetition, though it grows dull, hammers home the point that mental illness is just that: illness, not a character flaw. That is what this unwieldy book sets out to demonstrate, and a patient reader will find that in this it succeeds. Jennifer Blair, B.S. Yale University School of Medicine New Haven, CT Andre´s Martin, M.D., M.P.H. Yale Child Study Center New Haven, CT DOI: 10.1097/01.CHI.0000111372.22274.fa
Child and Adolescent Obesity: Causes, Consequences, Prevention and Management. By Walter Burniat, Tim Cole, Inge Lissau, and Elizabeth Poskitt. Cambridge, England: Cambridge University Press, 2002, 416 pp., $90.00 (hardcover). It is evident that clear-cut solutions to the obesity epidemic do not abound. A book on childhood and adolescent obesity should provide a comprehensive review and point out new directions. This volume, edited by renowned European experts, partially fulfills this expectation. Guillaume and Lissau address the alarming secular trends worldwide. However, the problems inherent to the definition of obesity, well pointed out by Cole et al., seemingly preclude an international comparison. It remains to be seen whether the solution proposed by the International Obesity Task Force and advocated by the authors will catch on: because the BMI cutoff for childhood and adolescent obesity was obtained by averaging the curve passing through the adult cutoff of 30 kg/m2 at age 18, approximately 1% of the British population below age 18 is currently obese. Obviously, this markedly contrasts with the 20% prevalence rate in the adult British population. Thus, the reference to age 18 (and not to the whole adult age range) implies a very conservative estimate in minors; the dependency of prevalence rates on the respective cutoffs is evident. Obviously, a standard reference population is required for research purposes to enable international comparisons. More importantly, the
J. AM. ACAD. CHILD ADOLESC. PSYCHIATRY, 43:4, APRIL 2004
factors underlying differences in national prevalence rates need to be determined. The volume is curiously slanted away from the biological findings that have been at the center stage of recent obesity research. For example, only two pages pertain to monogenic obesity (in the chapter by Wabitsch; as in most other chapters, references go only through the year 2000). Moreover, the results of virtually hundreds of twin, adoption, and family studies on energy expenditure, including activity levels, dietary intake and taste preferences, are dealt with in only two paragraphs (Guillaume and Lissau), despite the fact that particularly high heritability estimates for BMI have been obtained in adolescents. The unmentioned fact that the shared environment seemingly contributes only little to BMI variance between relatives should have been subjected to a critical analysis of the implications for both environmental causation and treatment. Providing obese adolescents and their parents with detailed information on the genetic basis of their condition can have a profound impact by reducing feelings of guilt. Are the authors (or are we) perhaps afraid of providing this information, concerned that families will stop addressing the problem? If so, we urgently need studies to document the effects of educating families on the genetic basis of obesity. It seems that there is a deeply rooted fear of genetic determinism, which is all too readily associated with therapeutic nihilism. Admittedly an extremely rare condition, inborn leptin deficiency serves as an example of how the advent of molecular research has yielded a successful treatment approach. In that context, is it that unlikely that the 2% to 4% of extremely obese children with mutations in the melanocortin-4 receptor gene might one day be similarly amenable to pharmacological interventions? The ongoing unraveling of pathways underlying energy homeostasis might even provide us with pharmacological interventions for the majority of obese individuals, in whom a genetic predisposition cannot currently be elucidated at the molecular level. A direct discussion of the pros and cons of the potential implications of these recent developments is largely lacking in the volume. Only in Europe are extremely obese children and adolescents treated over weeks to months as inpatients (Frelut). In light of both the burden imposed on patients and their families, and of the considerable treatment costs involved, it is of the utmost importance to assess medium- and long-term outcomes: Childhood obesity is too serious a public health issue for the field to become complacent or satisfied with the results provided by studies with typical follow-up rates of less than 50%. Whereas the few studies available indicate that BMI is lower in individuals recontacted after treatment, we know nothing about the many ones lost to follow-up. The chapter by Frelut argues that even if all those lost to follow505
BOOK REVIEWS
up eventually regained their weight, the positive results obtained among those remaining in treatment would still render the entire treatment program successful. However, we should also be concerned not to do any harm: are we that sure that some of the adolescents lost to follow-up might not be somatically and/or psychologically harmed by a weight loss of 25 kg within 6 months, and by subsequently regaining their baseline weights? Randomized controlled studies are urgently required. Almost every university hospital specializing in eating disorders has performed a thorough follow-up study on anorexia nervosa patients, and follow-up rates typically exceed 85%. We thus have a solid notion of how these patients fare medically and psychosocially. This positive situation is in marked contrast to the lack of such studies for extremely obese children and adolescents. Are mortality rates higher than in anorexia nervosa? What percentage of obese adolescents enter the job market? How socially isolated do they become, and what somatic and psychiatric disorders do they develop at what age, and how do these affect their body weight? Apart from these scientific issues, we would benefit from a better understanding of the course of childhood obesity over time. Case reports and series, generally lacking from the book, would certainly help to bring this about. The editors are to be applauded for addressing prevention prior to management. This sequence is clearly trend-setting. Indeed, “no current program for the treatment of obesity is particularly successful” (pp. 243–269). Without giving up hope that better treatment modalities might evolve in the future via new pharmacological developments, we need to shift much more from conventional treatments to prevention. The magnitude of the problem warrants continuation of the traditional biomedical approach, while at the same time implementing new preventive strategies. At the popu-
506
lation level, even small reductions in mean body weight are likely to have a substantial impact on obesity-related morbidity and mortality. We need to learn to appreciate this large effect at the population level. To achieve such changes, a truly interdisciplinary approach will be required. What can we do to get teachers, sociologists, media experts, and economists more interested in childhood obesity and devise creative new approaches? Finally, and as rightly pointed out in the last chapter, “The Future” (by James), we have to deal with the fact that “some components of the food industry are brilliantly organized in their political lobbying and marketing schemes.” As therapists we should not give up the fight when confronted with this aspect: too much is at stake. Professions involved in the treatment of obesity must make themselves heard at the political level. We need to convince our leadership that the obesity epidemic cannot be solved on an individual basis. Instead, political action is required to ensure that children and adolescents become more physically active and that healthy eating habits are established. Creativity and public pressure will be required to provide the food industry with incentives to reduce the exposure among children and adults to unhealthy food. If this approach fails, appropriate legislation may become necessary. Johannes Hebebrand, M.D. Clinical Research Group Department of Child and Adolescent Psychiatry Philipps University Marburg, Germany DOI: 10.1097/01.CHI.0000111373.22274.b3
Note to publishers: Books for review should be sent to Andre´s Martin, M.D., M.P.H., Yale Child Study Center, 230 South Frontage Road, P.O. Box 207900, New Haven, CT 06520-7900.
J. AM. ACAD. CHILD ADOLESC. PSYCHIATRY, 43:4, APRIL 2004