Behavioural and environmental factors are primarily responsible for the dramatic increase in obesity in the past two decades, although genes play an important role in regulation of body weight.
Calculating body mass index (BMI) is the most widely accepted method of screening for obesity in children. Abnormal BMI cut-offs in children are determined by age- and sex-specific percentiles.
The dramatic increase in childhood obesity has led to a marked increase in the diagnosis of impaired glucose tolerance and type 2 diabetes mellitus in children.
Preventing excessive weight gain in children is of paramount importance in confronting the obesity epidemic, as obesity is difficult to treat at all ages, and obese children tend to become obese adults.
The mainstay of treatment is lifestyle modification to improve diet and increase physical activity. Pharmacotherapy and bariatric surgery may be considered as an adjunct to lifestyle modification in severely obese adolescents.
Obesity is a condition of excessive body fat or adiposity that exceeds healthy limits. The most widely accepted method to screen for excess adiposity is calculation of body mass index (BMI).[1]Mei Z, Grummer-Strawn LM, Pietrobelli A, et al. Validity of body mass index compared with other body-composition screening indexes for the assessment of body fatness in children and adolescents. Am J Clin Nutr. 2002 Jun;75(6):978-85.
http://ajcn.nutrition.org/content/75/6/978.full
http://www.ncbi.nlm.nih.gov/pubmed/12036802?tool=bestpractice.com
Abnormal BMI cut-offs in children are determined by age- and sex-specific percentiles based on growth charts, as the amount of body fat changes with age and differs between boys and girls.[2]Ogden CL, Kuczmarski RJ, Flegal KM, et al. Centers for Disease Control and Prevention 2000 growth charts for the United States: improvements to the 1977 National Center for Health Statistics version. Pediatrics. 2002 Jan;109(1):45-60.
http://www.ncbi.nlm.nih.gov/pubmed/11773541?tool=bestpractice.com
Worldwide, the definition of overweight and obesity changes; however, a BMI >85th percentile is defined as overweight or at risk for overweight in the US and UK, a BMI ≥95th percentile is variably defined as obesity or overweight, and a BMI >99th percentile is defined as severe obesity.[3]Barlow SE. Expert Committee recommendations regarding the prevention, assessment, and treatment of child and adolescent overweight and obesity: summary report. Pediatrics. 2007 Dec;120(suppl 4):S164-92.
http://pediatrics.aappublications.org/content/120/Supplement_4/S164.full
http://www.ncbi.nlm.nih.gov/pubmed/18055651?tool=bestpractice.com
[4]Canoy D, Bundred P. Obesity in children. BMJ Clin Evid. 2011 Apr 4;2011. pii: 0325.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3217765/
http://www.ncbi.nlm.nih.gov/pubmed/21463538?tool=bestpractice.com
For children under 2 years of age, BMI percentiles are not available; thus, obesity may be defined as a weight ≥95th percentile for height.[3]Barlow SE. Expert Committee recommendations regarding the prevention, assessment, and treatment of child and adolescent overweight and obesity: summary report. Pediatrics. 2007 Dec;120(suppl 4):S164-92.
http://pediatrics.aappublications.org/content/120/Supplement_4/S164.full
http://www.ncbi.nlm.nih.gov/pubmed/18055651?tool=bestpractice.com