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Department of Pediatric Endocrinology
University of California Davis
2516 Stockton Blvd
Sacramento, CA 95817
E-mail:dmstyne{at}ucdavis.edu
This collection of presentations from a conference that was organized by the Pennisula Medical School at Plymouth, England, in May 2001 could not be more opportunely named. More than 30% of adult obesity begins in childhood, and the complications of obesity that begin in the young appear to be more serious than those from adult-onset obesity. The point of the contributors was to awaken interest in this progression and focus attention on important factors that contribute to the problem. These mostly English investigators offer much of value for other countries, including the United States.
Philip James, the leader of the International Obesity Task Force, points out the lack of recognition, until recently, of the rising prevalence of obesity, particulary of childhood obesity, across the world. He discusses the comorbidities of early onset obesity in the adults and the long-term metabolic effects of small-for-gestational-age birth on adult health. Remarkably, he shows how well-meaning programs that were meant to decrease the prevalence of malnutrition have inadvertently added to the prevalence of childhood obesity in some areas. He also points out that the standardized cutoff in the Western world for a healthy body mass index of 25 (in kg/m2) may be too high for some areas of Asia that see rising comorbidities at lower values of body mass index.
The discussion by Ken Fox opens with the astounding statement that the world may not have seen an epidemic such as obesity since the plague. He presents data from the United Kingdom that suggest that decreasing physical activity may exert a greater defect on the epidemic than increasing caloric intake; this matches the conclusions from some analyses of US national data. Although much of the available data relate to adults, he discusses the increasingly immobile childhood population and makes a strong case for a focus on decreasing inactivity rather than solely decreasing caloric intake, as is often the case.
The rise in the obesity epidemic over just a few decades strongly implicates environmental influence, rather than genetic change, as the basis of the problem. However, obesity has a strong genetic component over which the environment expresses its effects, and Philippe Froguel reviews what is known about monogenetic and polygenetic obesity in this context. Furthermore, techniques, such as candidate gene studies and genome-wide scans, that are now in use to determine the genes that are involved in obesity are explained with examples of results from the application of these techniques.
The thrifty phenotype hypothesis that is proposed by David Barker contends that low birth weight is related to later-life morbidity, mainly related to insulin resistance. Indeed, it has been well documented that insulin resistance or frank type 2 diabetes can now occur early in childhood. Terry Wilkin explains the basic concepts of insulin resistance. He then shows that in the Early Bird longitudinal study of children, the present weight of contemporary 5-y-olds, and not weight gain, catch-up growth, or birth weight, most closely correlates to insulin resistance at age 5 y. He points out important factors that deserve additional study, such as how to best detect insulin resistance, what factors proximally cause insulin resistance, and what can be done to prevent insulin resistance.
It is the primary care practitioners, not the endocrinologists, cardiologists, surgeons, etc, who are usually the first to treat persons affected by the epidemic. Ian Campbell reviews the magnitude of the problem and the challenges that the primary provider faces and makes useful suggestions for the treatment of adults.
Important barriers to achieving a healthy diet exist in the United Kingdom, and, as reviewed by Suzi Leather, the story looks similar to that of the United States. Small shops disappear and are replaced by supermarkets, which are sometimes located far from the neighborhoods that most require fresh produce. Because consumers are ill educated to choose a healthy diet and are often devoid of funds to buy healthy choices rather than highly produced foods, health education is the goal she recommends.
Obese persons are the object of jokes, all manners of sterotypes, and frequent social and economic hardships. They are frequently held responsible for their condition in a most personal manner, usually due to a perceived lack of will power. Andrew Hill reviews these and other issues in a discussion of self-image and the stigma of obesity. He wisely repeats the contention that obesity is not an abnormal response to a normal environment but a normal response to an abnormal environment. He pleas for a change in the obesogenic environment, a plea that may be read as a definition of the condition as a public health matter rather than as one of personal choice.
David Hall works in preventive care and addresses the issues in this important arena. He points out that much provider education is needed in the United Kingdom and that all avenues of prevention and treatment have not yet been explored. He discusses how simple and apparently obvious solutions may not be the best avenue; for example, screening for an elevated body mass index does not necessarily identify those persons who are most in need of intervention and in whom, without effective interventions, this may simply awaken concern without resolution.
The volume achieves its goal quite well. A focus on childhood, when much of obesity originates, is an appropriate target for the United Kingdom as well as for the rest of the world. The list of comorbidities, the complex world that has led to the blossoming of the problem, and the lack of efficacy of most treatments lead to the inexorable conclusion that prevention is the best approach on a population-wide basis. Some countries have accepted this tenant more vigorously than others. This volume, in company with many other works, surely supports such an approach.