Learn Multidisciplinary Management of Obesity in Children and Adolescents – Why and How Should It Be Achieved?

Definition and Epidemiology of Obesity

The degree of body fat mass depends upon ethnic background, gender,
developmental stage and age. The most useful non-invasive clinical measures to
define obesity are the body mass index (BMI, weight in kilograms divided by
the square of height in meters), waist circumference, waist-to-hip ratio (WHR,
to assess upper body fat deposition), and skinfold thickness [1–3].
Direct measurements of body fat content, e.g. hydrodensitometry, bioimpedance
or DEXA, are useful tools only in scientific studies. The BMI is easy
to calculate and correlates significantly with direct measures of body fatness.
Thus, it has become the standard parameter to define obesity clinically [1–4].
A child with a BMI above the 97th centile in regard to age and gender is considered
to be obese. A child with a BMI greater than the 90th but below the 97th
centile would be considered to be overweight [1–3, 5].
Projected rates for obesity (BMI 30kg/m 2) in adults in the United States
are 20% for the year 2000, 30% for the year 2015 and over 40% for the year
2025 [4, 6–8]. Similar to adults, childhood obesity has reached epidemic proportions
in all industrialized countries. The current age-adjusted prevalence may
be as high as 20–30%. In 1999, in a cross-sectional study in the city of Leipzig,
Germany, involving more than 2,500 children and adolescents between 7 and
18 years of age, revealed that 29% of the subjects were overweight (BMI between
90th and 97th centiles), and 16% were obese (BMI above 97th centile). In the
same geographical area, a population-based study revealed an incidence of
1. Factors contributing to the development of
obesity
Environmental/exogenous factors
• Increase of sedate activities (TV viewing)
• Decrease in physical activity
• Shift in diet towards more fast/prepackaged foods with
high fat/calorie content
• Loneliness and social isolation
• Psychosocial/family problems
Genetic/endogenous factors
Possibly polymorphisms and/or mutations in any of the
following:
• Adrenergic receptors
• Leptin
• Leptin receptors (Ob-R)
• Melanocortin receptor 4 (MC4-R)
• SOCS-3
• Tumor necrosis factor (TNF)
• Pro-opiomelanocortin (POMC)
• Melanocyte-concentrating hormone (MCH)
• Melanocortin receptor 3 (MC3-R)
• Neuropeptide Y (NPY)
• NPY receptors
• Corticotropin-releasing hormone (CRH)
• Thyrotropin-releasing hormone (TRH)
• Urocortin
• Orexin A and B
• Galanin
• Neurotensin
• Serotonin
• Others
obesity in children and adolescents of around 12% [2, 3]. Interestingly, not only
the number of obese children is increasing, but also the tendency towards even
more excessive weight [2, 3, unpubl. data].