Associations of Fat Mass and Fat-Free Mass with Physical Fitness in 4-Year-Old Children: Results from the MINISTOP Trial.

Pontus Henriksson,Cristina Cadenas-Sanchez,Marja Leppänen,Francisco Ortega,Marie Löf,Jeremy Pomeroy,Jonatan Ruiz,Christine Delisle Nyström

doi:10.3390/nu8080473

Abstract

Physical fitness is a powerful marker of health in youth. Studies in adolescents and adults suggest that higher fat mass is related to worse physical fitness. However, there is limited knowledge whether fat mass and fat-free mass are associated with physical fitness already in preschoolers. Baseline data from the MINISTOP (Mobile-based INtervention Intended to STop Obesity in Preschoolers) trial was utilized for this cross-sectional analysis. Body composition was assessed using air-displacement plethysmography. Fat mass index [fat mass (kg)/height2 (m)] and fat-free mass index [fat-free mass (kg)/height2 (m)] were used to provide height-adjusted measures of body composition. Physical fitness was measured using the PREFIT (FITness testing in PREschool children) battery, which assesses cardiorespiratory fitness, upper-body and lower-body muscular strength as well as motor fitness. In total, this study included 303 children (168 boys and 135 girls), who were on average 4.48 ± 0.15 years old. Higher fat mass index was associated with worse cardiorespiratory fitness (standardized β = −0.17, p = 0.002), lower-body muscular strength (β = −0.17, p = 0.003) and motor fitness (β = −0.21, p < 0.001) in regression analyses adjusted for age, sex and mutually adjusted for fat-mass index and fat-free mass index. Conversely, higher fat-free mass index was associated with better cardiorespiratory fitness (β = 0.18, p = 0.002), upper-body muscular strength (β = 0.39, p < 0.001), lower-body muscular strength (β = 0.22, p < 0.001) and motor fitness (β = 0.17, p = 0.004). Thus, fat mass and fat-free mass in preschoolers appear to have joint but opposite associations with physical fitness, an important marker for current and future health.

Highlights

Childhood obesity is a serious public health challenge [1] and the proportion of overweight and obese children is high in many countries [1,2]
Nutrients 2016, 8, 473 body fatness in childhood may have a negative impact on physical fitness [5,6,7,8], which is a potentially important observation since physical fitness is a powerful marker of health already in youth [4,9,10]
We further explored associations of Fat mass index (FMI) and fat-free mass index (FFMI) with physical fitness by visual representation of the standardized β-coefficients from the adjusted models, i.e., the change in physical fitness

Summary

Introduction

Childhood obesity is a serious public health challenge [1] and the proportion of overweight and obese children is high in many countries [1,2] This is of great concern since childhood obesity is associated with a higher risk of adult obesity [1,3] as well as impaired health [4] later in life. The few studies conducted in preschoolers suggest that a higher body mass index (BMI) is associated with a lower cardiorespiratory fitness [11,12,13,14,15] but with a higher upper-body muscular strength [12,16]. The aim of this study was to investigate the associations of FM and FFM with physical fitness in preschool-aged children

Objectives

Methods

Results

Conclusion