Obesity in children

Obesity in children has increased in recent decades. Behavioural and environmental factors are primarily responsible, 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.

Impaired glucose tolerance and type 2 diabetes mellitus are prevalent in children with obesity.

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. https://academic.oup.com/ajcn/article/75/6/978/4689425 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

A BMI between the 85th and 94th percentiles is defined as overweight, and a BMI ≥95th percentile (or ≥ to 30 kg/m2, which ever is lower) is defined as 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://www.ncbi.nlm.nih.gov/pubmed/18055651?tool=bestpractice.com [4]Centers for Disease Control and Prevention. About child & teen BMI. Mar 2021 [internet publication]. https://www.cdc.gov/healthyweight/assessing/bmi/childrens_bmi/about_childrens_bmi.html Severe obesity is defined as BMI of 120% of the 95th percentile.[5]Skinner AC, Ravanbakht SN, Skelton JA, et al. Prevalence of obesity and severe obesity in US children, 1999-2016. Pediatrics. 2018 Mar;141(3):e20173459. https://pediatrics.aappublications.org/content/141/3/e20173459.long http://www.ncbi.nlm.nih.gov/pubmed/29483202?tool=bestpractice.com [6]Kelly AS, Barlow SE, Rao G, et al. Severe obesity in children and adolescents: identification, associated health risks, and treatment approaches: a scientific statement from the American Heart Association. Circulation. 2013 Oct 8;128(15):1689-712. https://www.ahajournals.org/doi/10.1161/CIR.0b013e3182a5cfb3 http://www.ncbi.nlm.nih.gov/pubmed/24016455?tool=bestpractice.com For children aged <2 years, BMI normative values are not available. Weight-for-height values above the 95th percentile in this age group can be categorised as overweight.[7]Roy SM, Spivack JG, Faith MS, et al. Infant BMI or weight-for-length and obesity risk in early childhood. Pediatrics. 2016 May;137(5):e20153492. https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/27244803 http://www.ncbi.nlm.nih.gov/pubmed/27244803?tool=bestpractice.com

The World Health Organization 2006 growth standard is recommended in many countries for children aged 0–5 years, and for children aged 0–2 years in the US. WHO: Child growth standards. Opens in new window