Over the past few decades the incidence of obesity has doubled worldwide and current
estimates classify more than 1.5 billion adults as overweight and at least 500 million of them as
clinically obese, with body mass index (BMI) over 25 kg/m2 and 30 kg/m2, respectively. Obesity
prevalence rates are steadily rising in the majority of the modern Western societies, as well as in the
developing world. Moreover, alarming trends of weight gain are reported for children and adolescents,
undermining the present and future health status of the pediatric population. To highlight the
related threat to public health, the World Health Organization has declared obesity a global epidemic,
also stressing that it remains an under-recognized problem of the public health agenda
