Skeletal muscle mass reference curves for children and adolescents

Pediatr Obes. 2014 Aug;9(4):249-59. doi: 10.1111/j.2047-6310.2013.00168.x. Epub 2013 Jun 18.


Background: Skeletal muscle is key to motor development and represents a major metabolic end organ that aids glycaemic regulation.

Objectives: To create gender-specific reference curves for fat-free mass (FFM) and appendicular (limb) skeletal muscle mass (SMMa) in children and adolescents. To examine the muscle-to-fat ratio in relation to body mass index (BMI) for age and gender.

Methods: Body composition was measured by segmental bioelectrical impedance (BIA, Tanita BC418) in 1985 Caucasian children aged 5-18.8 years. Skeletal muscle mass data from the four limbs were used to derive smoothed centile curves and the muscle-to-fat ratio.

Results: The centile curves illustrate the developmental patterns of %FFM and SMMa. While the %FFM curves differ markedly between boys and girls, the SMMa (kg), %SMMa and %SMMa/FFM show some similarities in shape and variance, together with some gender-specific characteristics. Existing BMI curves do not reveal these gender differences. Muscle-to-fat ratio showed a very wide range with means differing between boys and girls and across fifths of BMI z-score.

Conclusions: BIA assessment of %FFM and SMMa represents a significant advance in nutritional assessment since these body composition components are associated with metabolic health. Muscle-to-fat ratio has the potential to provide a better index of future metabolic health.

Keywords: Bioelectrical impedance; centiles; fat-free mass; skeletal muscle mass.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorptiometry, Photon
  • Adipose Tissue / anatomy & histology*
  • Adipose Tissue / metabolism*
  • Adolescent
  • Body Composition
  • Body Mass Index
  • Body Weight
  • Child
  • Child, Preschool
  • Electric Impedance
  • Female
  • Glucose / metabolism*
  • Homeostasis
  • Humans
  • Male
  • Muscle, Skeletal / anatomy & histology*
  • Muscle, Skeletal / metabolism*
  • Nutritional Status
  • Reference Values
  • United Kingdom


  • Glucose