Ten per cent of the world’s school-aged children are estimated to be carrying excess body fat (Fig. 1), with an increased risk for developing chronic disease. Of these overweight children, a quarter are obese, with a significant likelihood of some having multiple risk factors for type 2 diabetes, heart disease and a variety of other co-morbidities before or during early adulthood. The prevalence of overweight is dramatically higher in economically developed regions, but is rising significantly in most parts of the world. In many countries the problem of childhood obesity is worsening at a dramatic rate. Surveys during the 1990s show that in Brazil and the USA, an additional 0.5% of the entire child population became overweight each year. In Canada, Australia and parts of Europe the rates were higher, with an additional 1% of all children becoming overweight each year. The burden upon the health services cannot yet be estimated. Although childhood obesity brings a number of additional problems in its train – hyperinsulinaemia, poor glucose tolerance and a raised risk of type 2 diabetes, hypertension, sleep apnoea, social exclusion and depression – the greatest health problems will be seen in the next generation of adults as the present childhood obesity epidemic passes through to adulthood. Greatly increased rates of heart disease, diabetes, certain cancers, gall bladder disease, osteoarthritis, endocrine disorders and other obesityrelated conditions will be found in young adult populations, and their need for medical treatment may last for their remaining life-times. The costs to the health services, the losses to society and the burdens carried by the individuals involved will be great. The present report has been written to focus attention on the issue and to urge policy-makers to consider taking action before it is too late. Specifically, the report:

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1467-789X.2004.00133.x

Obesity in children and young people: a crisis in public health.

The extreme obesity of the obese (ob/ob) mouse is attributable to mutations in the gene encoding leptin, an adipocyte-specific secreted protein which has profound effects on appetite and energy expenditure We know of no equivalent evidence regarding leptin's role in the control of fat mass in humans We have examined two severely obese children who are members of the same highly consanguineous pedigree Their serum leptin levels were very low despite their markedly elevated fat mass and, in both, a homozygous frame-shift mutation involving the deletion of a single guanine nucleotide in codon 133 of the gene for leptin was found The severe obesity found in these congenitally leptin-deficient subjects provides the first genetic evidence that leptin is an important regulator of energy balance in humans

/pdf/congenital-leptin-deficiency-is-associated-with-severe-early-2q6d7hsuzh.pdf

Congenital leptin deficiency is associated with severe early-onset obesity in humans

Objective To determine cut offs to define thinness in children and adolescents, based on body mass index at age 18 years. Design International survey of six large nationally representative cross sectional studies on growth. Setting Brazil, Great Britain, Hong Kong, the Netherlands, Singapore, and the United States. Subjects 97 876 males and 94 851 females from birth to 25 years. Main outcome measure Body mass index (BMI, weight/height2). Results The World Health Organization defines grade 2 thinness in adults as BMI Conclusions The proposed cut-off points should help to provide internationally comparable prevalence rates of thinness in children and adolescents.

https://www.bmj.com/content/bmj/335/7612/194.full.pdf

Body mass index cut offs to define thinness in children and adolescents: international survey

A review of 144 published studies of the relationship between socioeconomic status (SES) and obesity reveals a strong inverse relationship among women in developed societies. The relationship is inconsistent for men and children in developed societies. In developing societies, however, a strong direct relationship exists between SES and obesity among men, women, and children. A review of social attitudes toward obesity and thinness reveals values congruent with the distribution of obesity by SES in different societies. Several variables may mediate the influence of attitudes toward obesity and thinness among women in developed societies that result in the inverse relationship between SES and obesity. They include dietary restraint, physical activity, social mobility, and inheritance.

Socioeconomic Status and Obesity: A Review of the Literature

Reference curves for stature and weight in British children have been available for the past 30 years, and have recently been updated. However weight by itself is a poor indicator of fatness or obesity, and there has never been a corresponding set of reference curves to assess weight for height. Body mass index (BMI) or weight/height has been popular for assessing obesity in adults for many years, but its use in children has developed only recently. Here centile curves for BMI in British children are presented, from birth to 23 years, based on the same large representative sample as used to update the stature and weight references. The charts were derived using Cole's LMS method, which adjusts the BMI distribution for skewness and allows BMI in individual subjects to be expressed as an exact centile or SD score. Use of the charts in clinical practice is aided by the provision of nine centiles, where the two extremes identify the fattest and thinnest four per 1000 of the population.

https://adc.bmj.com/content/archdischild/73/1/25.full.pdf

Body mass index reference curves for the UK, 1990.

A weight-height index of adiposity should indicate the relative fatness of subjects of differing height unless obesity is itself correlated with height. The average body fat among adult women attending a hospital outpatient clinic for obesity was 40.5 percent of body weight. The height of an unselected series of 286 of these outpatients was found to be similar to that of the general population of women of similar age, which indicates that obesity in adult women is not significantly related to height. Body composition was measured by body density, body water and body potassium in a series of 104 female and 24 male subjects aged 14-60 years. In both sexes density, water and potassium gave progressively higher estimates of body fat (kg), and there was a significant difference between the values by different methods. The average of the estimates by these three methods was taken to be the 'true' value for each individual (F kg). Regression of F/H2 on W/H2 (Quetelet's index) gave a correlation coefficient of 0.955 for women and 0.943 for men. The deviation of the body fat estimated from Quetelet's formula from the 'true' value was not much greater than that when density, water or potassium were used as a basis for estimating body fat. It is concluded that Quetelet's formula is both a convenient and reliable indicator of obesity.

Quetelet's index (W/H2) as a measure of fatness

SECTION 1 Historical Perspective. Composition of the Body. Energy. Carbohydrates. Proteins. Fats. Alcohol: Its Metabolism and Effects. Fuels of Tissues. Energy Balance and Weight Regulation. Water and Monovalent Electrolytes. Bone Mineral. Iron, Zinc and Other Trace Elements. Fat-Soluble Vitamins. Water -Soluble Vitamins SECTION 2 Food Composition Tables. Cereals and Cereal Products. Vegetables, Fruits, Fungi and Their Products. Meat, Fish, Eggs and Novel Proteins. Milk and Milk Products, Fats and Oils. Beverages, Herbs and Spices. Food Processing. Pathogenic Agents in Food. Food Toxicity. Consumer Protection SECTION 3 Pregnancy and Lactation. Infant Nutrition. Childhood, Youth and Old Age. Exercise, Sport and Athletics SECTION 4 Nutritional Management of Clinical Undernutrition. Primary Protein-Energy Malnutrition. Sepsis and Trauma. Obesity. Nutritional Management of Diseases of the Stomach and Bowel. Nutrition and the Liver. Diabetes. Iodine Deficiency Disorders. Clinical Nutrition and Bone Disease. Dietary Factors in Dental Diseases. Nutritional Management of Diseases of the Blood. Diseases of the Kidney and Urinary Tract. Diseases of the Heart and Circulation: The Role of Dietary Factors in Aetiology and Management. Diet in Relation to the Nervous System. Skin and Hair. Nutrition and the Immune System. Nutritional Factors and Cancer. The Low-Birthweight Infant. Dietetic Treatment of Inherited Metabolic Disease. Nutritional Management of Alcohol-Related Disease. Eating Disorders. Drug-Nutrient Interactions. Policy and a Prudent Diet. Appendix 1: Methods for Dietary Assessment. Appendix 2: Dietary Reference Values. Index

Human Nutrition and Dietetics

We live today in an era of monographs in medicine and related physiologic and biochemical areas. The rapid increase in data in these fields has led to the production of reviews at short intervals. Reviews of this type are likely to suffer from one or both of two drawbacks. One of them is "the blight of the latest discovery." Most good biomedical monographs today are closely-knit, logically organized analyses of the most recent, data in a specific field. Such a compendium, seemingly eternal, or at least indestructible, can be turned to dust overnight by a few new data, or else by the development of a method somewhat less unrelated to the real world than are many of the methods currently used in biochemical research. Explaining what is known about a subject in terms of today's data and methods makes such monographs vulnerable to the effects of the sudden discovery of what, until a day before, was unknown.

Energy balance and obesity in man

Health implications of obesity definitions and usage measurement of energy stores including Quetelet's index measurement of energy intake measurement of energy expenditure aetiology of obesity in man possibilities for the treatment of obesity practical treatment strategies investigation and treatment of grade III and grade II obesity management of grade I and grade 0 obesity management of obesity with non-insulin-dependent diabetes management of obesity with hypertension or hyperlipidaemia other diseases associated with obesity obesity in pregnancy management and prevention of obesity in children obesity and health education. Appendices: weight-reducing diet energy and protein content of common foods.

J.S. Garrow

Papers

Quetelet's index (W/H2) as a measure of fatness

Human Nutrition and Dietetics

Energy balance and obesity in man

Obesity and Related Diseases

Treat Obesity Seriously: A Clinical Manual