Pontus Henriksson

Physical activity intensity, sedentary behavior, body composition and physical fitness in 4-year-old children: Results from the MINISTOP trial

Background:Existing knowledge on associations of physical activity (PA) and sedentary behavior (SB) with body composition and physical fitness in preschoolers is limited.Objective:To examine associations of PA and SB with body composition and physical fitness in healthy Swedish 4-year-old children.Methods:We utilized baseline data collected in 2014 for the population-based MINISTOP trial (n=307). Light-intensity PA (LPA), moderate-intensity PA (MPA), vigorous-intensity PA (VPA), moderate-to-vigorous PA (MVPA) and SB were measured using accelerometry (ActiGraph-wGT3x-BT). Body composition was measured using air-displacement plethysmography, and physical fitness (that is, cardiorespiratory fitness, lower and upper body muscular strength and motor fitness) was measured using the PREFIT fitness test battery. Multiple linear regression models adjusted for relevant confounders, and in addition, isotemporal substitution models were applied.Results:Greater MVPA was associated with lower fat mass percent (%FM, P=0.015), and greater VPA and MVPA were associated with higher fat-free mass index (FFMI, P=0.002 and P=0.011). In addition, greater VPA and MVPA were associated with higher scores for all physical fitness tests (P=0.042 to P<0.001). The results for MVPA were primarily due to VPA. SB was associated with weaker handgrip strength (P=0.031) when PA was not adjusted, but after adjusting also for VPA, the significant association disappeared (P=0.25). Substituting 5 min per day of SB, LPA or MPA with 5 min per day of VPA was associated with higher FFMI and better scores for cardiorespiratory fitness and motor fitness. Correspondingly, substituting 5 min per day of VPA with SB or LPA was associated with weaker performance for lower muscular strength.Conclusions:Time spent on VPA was associated with higher FFMI and better physical fitness. The results suggest that promoting VPA may be important to improve childhood body composition and physical fitness already at an early age.

Total body fat content versus BMI in 4-year-old healthy Swedish children.

Childhood overweight and obesity, a worldwide problem, is generally identified using BMI (body mass index). However, this application of BMI has been little investigated in children below 5 years of age due to a lack of appropriate methods to assess body composition. Therefore, we used air displacement plethysmography (ADP) to study 4.4-year old boys and girls since this method is accurate in young children if they accept the requirements of the measurement. The purpose was to analyze the relationship between BMI and body fat in these children. Body composition was assessed in 76 (43 boys, 33 girls) of the 84 children brought to the measurement session. Boys and girls contained 25.2 ± 4.7 and 26.8 ± 4.0% body fat, respectively. BMI-based cut-offs for overweight could not effectively identify children with a high body fat content. There was a significant (P < 0.001) but weak (r = 0.39) correlation between BMI and body fat (%). In conclusion, requirements associated with a successful assessment of body composition by means of ADP were accepted by most 4-year-olds. Furthermore, BMI-based cut-offs for overweight did not effectively identify children with a high body fatness and BMI explained only a small proportion of the variation in body fat (%) in this age group.

Gestational weight gain according to Institute of Medicine recommendations in relation to infant size and body composition

Intrauterine life may be a critical period for programming childhood obesity; however, there is insufficient knowledge concerning how gestational weight gain (GWG) affects infant fat mass (FM) and fat‐free mass (FFM).

Mobile-based intervention intended to stop obesity in preschool-aged children: the MINISTOP randomized controlled trial

Background: Traditional obesity prevention programs are time- and cost-intensive. Mobile phone technology has been successful in changing behaviors and managing weight; however, to our knowledge, its potential in young children has yet to be examined.Objective: We assessed the effectiveness of a mobile health (mHealth) obesity prevention program on body fat, dietary habits, and physical activity in healthy Swedish children aged 4.5 y.Design: From 2014 to 2015, 315 children were randomly assigned to an intervention or control group. Parents in the intervention group received a 6-mo mHealth program. The primary outcome was fat mass index (FMI), whereas the secondary outcomes were intakes of fruits, vegetables, candy, and sweetened beverages and time spent sedentary and in moderate-to-vigorous physical activity. Composite scores for the primary and secondary outcomes were computed.Results: No statistically significant intervention effect was observed for FMI between the intervention and control group (mean ± SD: -0.23 ± 0.56 compared with -0.20 ± 0.49 kg/m2). However, the intervention group increased their mean composite score from baseline to follow-up, whereas the control group did not (+0.36 ± 1.47 compared with -0.06 ± 1.33 units; P = 0.021). This improvement was more pronounced among the children with an FMI above the median (4.11 kg/m2) (P = 0.019). The odds of increasing the composite score for the 6 dietary and physical activity behaviors were 99% higher for the intervention group than the control group (P = 0.008).Conclusions: This mHealth obesity prevention study in preschool-aged children found no difference between the intervention and control group for FMI. However, the intervention group showed a considerably higher postintervention composite score (a secondary outcome) than the control group, especially in children with a higher FMI. Further studies targeting specific obesity classes within preschool-aged children are warranted. This trial was registered at clinicaltrials.gov as NCT02021786.

Assessment and prediction of thoracic gas volume in pregnant women: an evaluation in relation to body composition assessment using air displacement plethysmography.

Assessment of body fat (BF) in pregnant women is important when investigating the relationship between maternal nutrition and offspring health. Convenient and accurate body composition methods applicable during pregnancy are therefore needed. Air displacement plethysmography, as applied in Bod Pod, represents such a method since it can assess body volume (BV) which, in combination with body weight, can be used to calculate body density and body composition. However, BV must be corrected for the thoracic gas volume (TGV) of the subject. In non-pregnant women, TGV may be predicted using equations, based on height and age. It is unknown, however, whether these equations are valid during pregnancy. Thus, we measured the TGV of women in gestational week 32 (n 27) by means of plethysmography and predicted their TGV using equations established for non-pregnant women. Body weight and BV of the women was measured using Bod Pod. Predicted TGV was significantly (P = 0·033) higher than measured TGV by 6 % on average. Calculations in hypothetical women showed that this overestimation tended to be more pronounced in women with small TGV than in women with large TGV. The overestimation of TGV resulted in a small but significant (P = 0·043) overestimation of BF, equivalent to only 0·5 % BF, on average. A Bland-Altman analysis showed that the limits of agreement were narrow (from -1·9 to 2·9 % BF). Thus, although predicted TGV was biased and too high, the effect on BF was marginal and probably unimportant in many situations.

The Two-Component Model for Calculating Total Body Fat from Body Density: An Evaluation in Healthy Women before, during and after Pregnancy

A possibility to assess body composition during pregnancy is often important. Estimating body density (DB) and use the two-component model (2CM) to calculate total body fat (TBF) represents an option. However, this approach has been insufficiently evaluated during pregnancy. We evaluated the 2CM, and estimated fat-free mass (FFM) density and variability in 17 healthy women before pregnancy, in gestational weeks 14 and 32, and 2 weeks postpartum based on DB (underwater weighing), total body water (deuterium dilution) and body weight, assessed on these four occasions. TBF, calculated using the 2CM and published FFM density (TBF2CM), was compared to reference estimates obtained using the three-component model (TBF3CM). TBF2CM minus TBF3CM (mean ± 2SD) was −1.63 ± 5.67 (p = 0.031), −1.39 ± 7.75 (p = 0.16), −0.38 ± 4.44 (p = 0.49) and −1.39 ± 5.22 (p = 0.043) % before pregnancy, in gestational weeks 14 and 32 and 2 weeks postpartum, respectively. The effect of pregnancy on the variability of FFM density was larger in gestational week 14 than in gestational week 32. The 2CM, based on DB and published FFM density, assessed body composition as accurately in gestational week 32 as in non-pregnant adults. Corresponding values in gestational week 14 were slightly less accurate than those obtained before pregnancy.

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

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.

Parental fat-free mass is related to the fat-free mass of infants and maternal fat mass is related to the fat mass of infant girls.

Existing studies suggest that weight and body composition of parents influence the size and body composition of their offspring, but are often inconclusive and conducted by means of inappropriate body composition methodology. Our aim was to study infant size and body composition variables in relation to body composition variables of their mothers and fathers in a well‐nourished population using an accurate methodology.

Variation in the fat mass and obesity-related (FTO) genotype is not associated with body fatness in infants, but possibly with their length

Data relating variation at the fat mass and obesity‐related (FTO) locus (rs9939609) to fat mass in infancy are inconclusive.

A whole brain volumetric approach in overweight/obese children: Examining the association with different physical fitness components and academic performance. The ActiveBrains project

Abstract Obesity, as compared to normal weight, is associated with detectable structural differences in the brain. To the best of our knowledge, no previous study has examined the association of physical fitness with gray matter volume in overweight/obese children using whole brain analyses. Thus, the aim of this study was to examine the association between the key components of physical fitness (i.e. cardiorespiratory fitness, speed‐agility and muscular fitness) and brain structural volume, and to assess whether fitness‐related changes in brain volumes are related to academic performance in overweight/obese children. A total of 101 overweight/obese children aged 8–11 years were recruited from Granada, Spain. The physical fitness components were assessed following the ALPHA health‐related fitness test battery. T1‐weighted images were acquired with a 3.0 T S Magnetom Tim Trio system. Gray matter tissue was calculated using Diffeomorphic Anatomical Registration Through Exponentiated Lie algebra (DARTEL). Academic performance was assessed by the Batería III Woodcock‐Muñoz Tests of Achievement. All analyses were controlled for sex, peak high velocity offset, parent education, body mass index and total brain volume. The statistical threshold was calculated with AlphaSim and further Hayasaka adjusted to account for the non‐isotropic smoothness of structural images. The main results showed that higher cardiorespiratory fitness was related to greater gray matter volumes (P < 0.001, k = 64) in 7 clusters with &bgr; ranging from 0.493 to 0.575; specifically in frontal regions (i.e. premotor cortex and supplementary motor cortex), subcortical regions (i.e. hippocampus and caudate), temporal regions (i.e. inferior temporal gyrus and parahippocampal gyrus) and calcarine cortex. Three of these regions (i.e. premotor cortex, supplementary motor cortex and hippocampus) were related to better academic performance (&bgr; ranging from 0.211 to 0.352; all P < 0.05). Higher speed‐agility was associated with greater gray matter volumes (P < 0.001, k = 57) in 2 clusters (i.e. the inferior frontal gyrus and the superior temporal gyrus) with &bgr; ranging from 0.564 to 0.611. Both clusters were related to better academic performance (&bgr; ranging from 0.217 to 0.296; both P < 0.05). Muscular fitness was not independently associated with greater gray matter volume in any brain region. Furthermore, there were no statistically significant negative association between any component of physical fitness and gray matter volume in any region of the brain. In conclusion, cardiorespiratory fitness and speed‐agility, but not muscular fitness, may independently be associated with greater volume of numerous cortical and subcortical brain structures; besides, some of these brain structures may be related to better academic performance. Importantly, the identified associations of fitness and gray matter volume were different for each fitness component. These findings suggest that increases in cardiorespiratory fitness and speed‐agility may positively influence the development of distinctive brain regions and academic indicators, and thus counteract the harmful effect of overweight and obesity on brain structure during childhood. HighlightsPhysical fitness components are positively associated with gray matter volumes in overweight/obese children.Cardiorespiratory fitness and speed‐agility affect development of distinctive brain regions.Cardiorespiratory fitness and speed‐agility related‐changes in brain volumes are associated with better academic performance.Muscular fitness is not associated with cortical and subcortical brain volumes.Physical activity that involves aerobic exercise and motor‐agility tasks is important for the brain and academic performance.