Högskolan i Skövde

Objective: To examine the associations between BMI trajectories and changes in fat-free mass index (FFMI) and fat mass index (FMI), assessed via bioelectrical impedance analysis (BIA) and skinfold thickness (ST).

Methods: The study included 4708 European children with BIA data and 3627 with ST data, aged 2–9.9 years at baseline, participating in two waves of the IDEFICS (IDEFICS (Identification and Prevention of Dietary- and Lifestyle-Induced Health Effects in Children and Infants))/I.Family (I. Family (Determinants of eating behavior in European children, adolescents, and their parents)) studies (w0: 2007/08; w2: 2013/14). Children were classified into three BMI trajectory groups: retained normal weight (RNW), remained overweight/obese (ROO), and excessive weight gain (EWG). Analyses of covariance evaluated differences in BMI z-score changes, FFMI, and FMI across groups. Mixed-effects linear regression assessed associations between BMI z-score changes and FFMI/FMI over time.

Results: BMI z-score changes were more strongly associated with FMI (β = 1.16–1.70 in boys; 1.17–1.62 in girls, p < 0.05) than with FFMI, for both BIA and ST. In ROO and EWG groups, associations with FMI were consistently stronger, except among girls <6 years in the ROO group (BIA). In the RNW group, boys >6 years showed stronger associations with FFMI.

Conclusions: Associations between BMI changes and FFMI/FMI vary by BMI trajectory and body composition method. BIA showed closer alignment with BMI changes than ST. These findings suggest that BMI alone may not adequately capture changes in specific body compartments. While convenient, BMI should be interpreted with caution, especially when fat or fat-free mass plays a differential role in disease risk or health outcomes.

Global reporting of obesity is commonly based on comparisons over multiple decades1 and lacks a granular and systematic analysis of its dynamics. We used 4,050 population-based studies with measured height and weight data on 232 million participants to assess the worldwide dynamics of obesity from 1980 to 2024. The rise in obesity decelerated in school-aged children and adolescents throughout the 1990s in many high-income countries, and subsequently plateaued in most at age-standardized prevalences spanning 20 percentage points, from 3–4% for girls in Japan, Denmark and France to 23% for boys in the USA. There were indications of a small decline in obesity in children and adolescents in some high-income western countries (for example, Italy, Portugal and France) since the 2000s. Similar trends were seen in some countries in Central and Eastern Europe. In adults, the rise in obesity slowed down in high-income western countries about a decade after children, followed by a plateau or possibly a small reversal of the rise in some countries (for example, Spain). In most low-income and middle-income countries, the annual absolute change in prevalence has remained stable or increased over time, even though prevalence has surpassed that of high-income countries. These highly varied dynamics suggest that the social, economic and technological trends that influence the availability, affordability and use of different foods may have helped control the rise in obesity in high-income countries, but require policy interventions in low-income and middle-income countries.

Introduction: The pandemic caused by SARS-CoV-2 is having, and will continue to have, devastating indirect consequences, particularly in developing countries. Understanding vaccine acceptance, knowledge, and attitudes among healthcare workers is crucial, as they influence public opinion, community uptake, and vaccination decision-making. This study aimed to identify variables associated with SARS-CoV-2 vaccine uptake, knowledge, and attitude among health workers in level 2 and 3 facilities in Nairobi, Kenya.

Methods: A quantitative questionnaire was distributed to healthcare workers, and chi-square tests, Fisher's exact tests, t-tests, and one-way ANOVA were conducted to determine associations between variables.

Results: Vaccine uptake was significantly associated with knowledge index (p = 0.04), and nurses, assistant nurses, and physicians were more likely to be vaccinated than other health professions (p = 0.03). Knowledge index was significantly associated with age (p = 0.03), being female (p = 0.03), years of experience (p = 0.02), being vaccinated (p = 0.01), and attitude index (p < 0.01). A significant association was found between knowledge index and subcounty (p = 0.03). Dagoretti South, Embakasi East and Westlands had the lowest knowledge indexes among the subcounties. Attitude index was significantly associated with years of experience (p = 0.02), being vaccinated (p < 0.01), knowledge index (p < 0.01), and profession (p = 0.03).

Discussion: Despite high vaccination uptake and generally positive attitudes, essential knowledge gaps regarding COVID-19 vaccines persist. The knowledge gaps include COVID-19 vaccine myths such as believing that, or being unsure whether, the vaccine can alter genes, increase autoimmune diseases, or cause COVID-19 disease to the receiver. These findings highlight the importance of addressing vaccine misconceptions and improving health literacy to strengthen vaccination strategies and pandemic preparedness among primary health workers.

Unhealthy food cues are omnipresent and promote overconsumption. Although childhood obesity rates are increasing, there is no strict regulation of the marketing of unhealthy foods towards children. This is problematic since the human brain, especially areas important for cognitive control, continues to develop into the 30s. It is not known in how far the brain response to unhealthy food cues varies with body mass index (BMI) and age. To investigate this, 168 children (10–17 y) and 182 adults (30–67 y) from the European IDEFICS cohort were scanned with the use of fMRI while viewing pictures of healthy and unhealthy foods. Children exhibited lower activation in the right dorsolateral prefrontal cortex (dlPFC) compared to adults when exposed to unhealthy food cues. Across all age groups, individuals with higher BMI demonstrated reduced activation in the middle cingulum in response to unhealthy food stimuli. Lastly, the relation between BMI and brain activation in response to unhealthy compared with healthy food stimuli varied with development: in children, higher BMI was correlated with decreased activation in right anterior insula and right dlPFC, whereas no such relationship was observed in adults. These findings suggest that children with higher BMI may be particularly vulnerable to unhealthy food cues. In this light, the lack of regulation regarding unhealthy food marketing targeted at children is concerning, especially considering the global increase in obesity rates.

Background and aims: Early life factors have been suggested to be associated with later cardiometabolic risk in children, adolescents and adults. Our study aimed to investigate the associations between early life factors and metabolic syndrome (MetS) in children and adolescents.

Methods and results: Our analysis sample comprised of 8852 children aged 2–9 years at baseline that participated in up to three examination waves of the pan-European IDEFICS/I.Family cohort (baseline: 2007/08, 1st follow-up 2009/10, 2nd follow-up 2013/14). Mixed-effects models were used to estimate the associations between early life factors and MetS score and z-scores of waist circumference (WC), systolic (SBP) and diastolic blood pressure (DBP), Homeostasis Model Assessment for Insulin Resistance, high density lipoprotein cholesterol (HDL) and triglycerides. Being born large for gestational age (LGA) showed a positive association with MetS score (β = 0.67; 99%CI 0.44, 0.90) and with WC z-score (β = 0.51; 99%CI 0.39, 0.63) and was weakly inversely associated with HDL z-score. Being born small for gestational age (SGA) was associated with lower WC z-score (ß = −0.26; 99%CI -0.37, −0.16), with a lower MetS score (ß = −0.13; 99%CI −0.33, 0.08) and slightly higher z-scores of SBP and DBP. Weight gain during pregnancy was positively associated with MetS score and WC z-score while premature birth was positively associated with SBP.

Conclusions: Children born LGA, SGA or preterm may warrant closer monitoring to prevent MetS later on. 

It remains unclear how serum 25-hydroxyvitamin D (25(OH)D) concentrations relate to childhood bone health. We hypothesized that 25(OH)D was inversely associated with bone turnover biomarkers and positively associated with bone stiffness. Cross-sectional analyses were performed using data from participants (2-15-year-old, 51% boys) from the Identification and Prevention of Dietary- and Lifestyle-induced Health Effects in Children and Infants Study (IDEFICS)/I.Family cohort, comprising 3,638 serum 25(OH)D measurements collected in 2007-2008 and 2012-2013 across eight European countries. A biomarker of bone formation (serum osteocalcin), a biomarker of bone resorption (serum C-terminal telopeptides of type I collagen [CTx]), and stiffness index measured using calcaneal quantitative ultrasound were considered outcomes. Linear mixed-effects models were used to adjust for confounders (i.e., age, sex, parental education, time spent in sports club, dairy products consumption, sedentary behavior, height and weight z-scores), the cluster effect of country and repeated measurements. Interactions of calcium intake, moderate-to-vigorous physical activity (MVPA) and weight status with 25(OH)D on outcomes were tested. Only 1 in 3 participants reached the sufficient 25(OH) D concentration of 20 ng/mL. Sufficient 25(OH)D was associated with higher stiffness index if participants had MVPA ≥60 min/day (β = 12.14, P < .05). Moreover, 25(OH)D was inversely associated with CTx (β = –7.09, P < .05); this association was positive but not statistically significant among primary school children living with overweight/obesity. No interaction was observed for calcium intake. In conclusion, serum 25(OH)D and CTx were inversely associated. MVPA interacted with the positive association between 25(OH)D and bone stiffness, highlighting the importance of promoting MVPA guidelines in future vitamin D and bone health interventions.

PURPOSE: It is assumed that sensory taste perception shapes food choices and impacts dietary intake. However, this has rarely been studied in free living subjects of different age-groups with standardised methods. The present study investigated the association of the ability to rank sweet and fat taste intensities with consumption frequency of sweet and fatty foods in children, adolescents and adults from eight European countries.

METHODS: In total, 461 children, 421 adolescents and 612 adults from the IDEFICS/I.Family cohort participated in sensory sweet and fat intensity rating tests. Sweet and fatty food consumption frequencies were assessed using a food frequency questionnaire. The association between the ability to rank sweet and fat intensity with sweet and fatty food consumption frequencies was estimated using linear mixed regression models adjusting for weight status, country, sex, age and family affiliation.

RESULTS: Across all age groups, the largest proportion of participants had medium sweet and fat taste intensity ranking abilities. The next largest proportion had low sweet and fat taste intensity rating abilities, while the smallest proportion had high intensity rating abilities to sweet and fat taste. A negative association of sweet and fat taste intensity ranking ability with sweet and fatty food consumption frequencies was found for children. In adolescents, the association was positive. In adults, there was no association.

CONCLUSION: It seems that the association of taste intensity ratings with food consumption frequencies during adolescence differs from the associations in children and adults. This could be due to hormonal changes during puberty, growth and maturation. Thus, further research focussing on maturation processes in association with taste perception during adolescence may be required.

Background: Reference values of ferritin and transferrin for European children do not exist. Objective: We aimed to provide sex-, age-, and body mass index (BMI)-specific serum ferritin and transferrin reference percentiles of 3–15-y-old children based on cohort data and to investigate determinants of iron status. Methods: A total of 3390 ferritin and 3416 transferrin measurements from children residing in 8 European countries participating in the IDEFICS/I.Family cohort (https://www.isrctn.com/ISRCTN62310987) at baseline (W0) and 6 y later (W3) were used to estimate percentiles using the generalized additive model for location, scale and shape. Associations of serum ferritin and transferrin concentrations with total iron intake, total iron intake additionally adjusted for vitamin C intake, and iron from heme sources were investigated separately with adjustment for sex, age, country of residence, parental education, usual energy intake and BMI z-score in regression models using cross-sectional and longitudinal data. Results: The age-specific ferritin and transferrin 5th and 95th reference percentiles ranged from 10.9 to 81.1 μg/L and 2.23 to 3.56 g/L, respectively. A deficient iron status was observed in 3% of children at W0 and 7% of children and adolescents at W3, respectively. At both waves, a higher iron intake from heme sources was positively associated with serum ferritin {W0: β = 3.21 [95% confidence interval (CI): 0.71, 5.71]; W3: β = 4.48 [95% CI: 2.09, 6.87]}, that is, children consuming one mg more heme iron had a 3.21 and 4.48 μg/L higher ferritin concentration. Adherence to a mainly vegetarian diet was associated with a lower chance for sufficient serum ferritin cross-sectionally at W3 [odds ratio (OR) 0.40 (95% CI: 0.21, 0.81)] and longitudinally [OR 0.35 (95% CI: 0.15, 0.93)]. Conclusions: Age-, sex-, and BMI-specific reference percentiles of serum ferritin and transferrin concentrations based on cohort data are provided for European children aged 3–15 y and may be used in clinical practice. 

Dietary diversity (DD) plays a crucial role in fostering high-quality diets, but its association with health outcomes, particularly body adiposity and non-communicable diseases (NCDs), is inconsistent. This may be due to a lack of a standardized method for estimating DD. Our study investigates the association between two DD indices, namely the dietary diversity score (DDS) and food variety score (FVS), and anthropometric measures, biochemical parameters, and diet quality in a large population sample from the I.Family study across research centers in eight European countries. In our cross-sectional analysis of 3035 participants, DDSs varied among countries, with a higher prevalence in the third DDS tertile among those with higher education. DDS showed a positive association with diet quality across all age groups. Higher DDS tertile individuals showed increased fiber, fruit, and vegetable intake, greater meal frequency, and lower ultra-processed food consumption. No relevant biochemical differences were observed across DDS tertiles, and a higher DDS was associated with lower overweight/obesity prevalence only in adults. No significant associations were found with FVS. Our findings emphasize the need to consider food groups for a more accurate estimation of diet quality. This aligns with studies suggesting DDS alone is not an independent risk factor for obesity in children and adolescents. Public health programs should prioritize food diversity to promote improved nutrition and overall well-being in communities. 

The digital environment can pose health risks through exposure to unhealthy content. Yet, little is known about its relation to children’s cognitive functioning. This study investigates the association between digital media (DM) exposure and children’s cognitive functioning. This cross-sectional study is based on examinations of children aged 8–18 years (N = 8673) of the I.Family cohort (2013–2014). Exposure to television, computer, smartphone and internet was self-reported (hours/day). Media multitasking (MMT) was defined as simultaneous use of computers with other digital or non-screen-based activities. Standard instruments were used to assess cognitive inflexibility (score: 0–39), decision-making ability (− 100 to + 100) and impulsivity (12–48). Adjusted regression coefficients and 99.9%CIs were calculated by generalized linear mixed-effects models. In total, 3261 participants provided data for impulsivity, 3441 for cognitive inflexibility and 4046 for decision-making. Exposure to smartphones and media multitasking were positively associated with impulsivity (βsmartphone = 0.74; 99.9%CI = 0.42–1.07; βMMT = 0.73; 99.9%CI = 0.35–1.12) and cognitive inflexibility (βsmartphone = 0.32; 99.9%CI = -0.02–0.66; βMMT = 0.39; 99.9%CI = 0.01–0.77) while being inversely associated with decision-making ability. Extensive smartphone/internet exposure combined with low computer/medium TV exposure was associated with higher impulsivity and cognitive inflexibility scores, especially in girls. DM exposure is adversely associated with cognitive functioning in children and adolescents. Children require protection against the likely adverse impact of digital environment.