In the past, obesity was regarded as a public health problem leading to reduced life expectancy that affected only the developed world. Obesity has now become a problem of developing countries as well largely as a result of the adoption of Western lifestyles. Central obesity in particular is associated with increased risk of cardiovascular and metabolic diseases. The study discussed in this book was conducted in six secondary schools (public and private) in Lagos, Nigeria and involved 1,100 adolescents. Over all prevalence of overweight and obesity was 5.8% and 1.7% respectively. The prevalence of overweight and obesity was higher in private than public schools and girls were more affected than boys. Of all the anthropometric indices of central obesity measured, waist circumference was demonstrated to have a strongly positive correlation with Body mass index (BMI). Waist circumference is therefore advocated as a screening and monitoring tool in the management of obesity. Prevention of obesity should begin in childhood as the prevalence is higher in early adolescence. It should be noted that families, health care providers and health policy makers all have a role to play.