A Narrative Review of Medical and Genetic Risk Factors among Children Age 5 and Younger with Severe Obesity

Child Obes. 2018 Oct;14(7):443-452. doi: 10.1089/chi.2017.0350. Epub 2018 May 23.


Severe obesity defined as an age- and gender-specific body mass index ≥120% of the 95th percentile in children younger than 5 years is well recognized as a significant challenge for prevention and treatment. This article provides an overview of the prevalence, classification of obesity severity, patterns of weight gain trajectory, medical and genetic risk factors, and comorbid disorders among young children with an emphasis on severe obesity. Studies suggest rapid weight gain trajectory in infancy, maternal smoking, maternal gestational diabetes, and genetic conditions are associated with an increased risk for severe obesity in early childhood. Among populations of young children with severe obesity seeking care, co-morbid conditions such as dyslipidemia and fatty liver disease are present and families report behavioral concerns and developmental delays. Children with severe obesity by age 5 represent a vulnerable population of children at high medical risk and need to be identified early and appropriately managed.

Keywords: genetics; medical complications; risk factors; severe obesity; young children.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Body Mass Index
  • Child, Preschool
  • Comorbidity
  • Diabetes, Gestational
  • Dyslipidemias / epidemiology
  • Ethnicity
  • Female
  • Genetic Predisposition to Disease*
  • Humans
  • Infant
  • Insulin Resistance
  • Male
  • Maternal Behavior
  • Non-alcoholic Fatty Liver Disease / epidemiology
  • Obesity, Morbid / epidemiology*
  • Obesity, Morbid / prevention & control
  • Obesity, Morbid / therapy
  • Pediatric Obesity / epidemiology*
  • Pediatric Obesity / prevention & control
  • Pediatric Obesity / therapy
  • Pregnancy
  • Prenatal Exposure Delayed Effects
  • Risk Factors
  • Smoking / adverse effects
  • Socioeconomic Factors
  • Weight Gain