Prevalence of underweight in children and adolescents (aged 3-18 years) from Kraków (Poland) in 1983 and 2010

Underweight among adolescents in Denmark: prevalence, trends (1998-2018), and association of underweight with socioeconomic status

BACKGROUND

Underweight among adolescents is an important clinical and public health issue. It is associated with adverse health outcomes throughout the life-span and may reflect food poverty, unhealthy eating habits, or some underlying health conditions.

OBJECTIVE

To study prevalence and trends in underweight among adolescents 1998-2018, to examine social inequality in underweight, and whether social inequality changed over time.

METHODS

Data were derived from 6 cross-sectional school surveys from The Health Behaviour in School-aged Children study in Denmark. The study included 11-, 13-, and 15-year-old schoolchildren in random samples of schools in 1998, 2002, 2006, 2010, 2014, and 2018 (n = 22,177). Underweight was determined by body mass index-for-age thinness grade 2-3 (the Cole and Lobstein method). Socioeconomic status was determined using occupational social class (the Danish OSC Measurement).

RESULTS

The overall prevalence of underweight was 3.1% among boys and 5.3% among girls (P < 0.0001) and decreased by age (P < 0.0001) among both boys and girls. The prevalence of underweight was almost stable from 1998 to 2018. There was no observed absolute or relative social inequality in the prevalence of underweight among boys or girls.

CONCLUSION

The prevalence of underweight in 11- to 15-year-olds was significantly higher among girls than boys. The prevalence remained stable from 1998 to 2018. There was no significant association between SES and prevalence of underweight. It is important to elucidate the underlying causes of underweight such as malnutrition, eating disorders, eating problems, loss of appetite, chronic diseases, insufficient knowledge of nutrients effects on bodily functions, and persistent pain.

Longitudinal Analysis (1994-2020) of Prevalence and Trends of Underweight in Polish Children

Nutritional status disorders are a worldwide problem. Approximately 5.9 million children under the age of five die each year, and 45% of these deaths are related to malnutrition. The aim of the study was to analyse the prevalence of underweight children aged between 6 and 7 years old, living in the Gdańsk, Poland, in the years 1994–2020. The anthropometric parameters of 67,842 children were analysed. BMI (Body Mass Index) value <5 percentile (pc) was defined as underweight. The BMI value was compared to the WHO (World Health Organization) centile charts and the OLAF (research project PL0080) national reference charts. The prevalence of underweight children in relation to the WHO charts was 1.9%; underweight status was found to be more significant in the group of boys (2.1%) than the group of girls (1.7%) (p < 0.001). According to the OLAF centile charts, the underweight figure among all of the study population was 2.1% and no statistical significance between boys (2.1%) and girls (2.0%) was found (p = 0.670). The occurrence of underweight indviduals in the studied group slightly increased in the years 1994–2020. We found a statistically significant increasing linear trend in the analysis of underweight children in our group (p < 0.001), in group of boys (p < 0.001), but not girls (WHO p = 0.603; OLAF p = 0.787). This points to the need to conduct regular screening systems for children and adolescents.

Weight status and body composition analysis among Polish boys with autism spectrum disorders

Currently, autism spectrum disorders (ASD) are one of the main health care problems in both Poland and in other countries. There are limited studies on the physical growth and body composition among children and adolescents with ASD. Several studies have indicated that the prevalence of unhealthy weight is high among autistic patients. Therefore, the main aim of this study was to assess the prevalence of underweight, overweight and obesity of Polish boys with ASD and to analyse body composition.

A cross-sectional study was performed on 29 Polish boys aged 3–11 with autism. Anthropometric measurements were taken. Bioelectrical impedance analysis (BIA) was used to evaluate body composition. The percentile values and z-scores for body height, body weight and BMI were calculated. The CDC cut–points were used to determine weight status. Statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS) version 25.

16.1% autistic boys had z-scores for body weight above two standard deviations, 12.9% had z-scores for body height above two standard deviations and z-scores for BMI above two standard deviations were found in 19.4% of the boys. 13.8% of autistic boys were underweight, 48.3% had healthy weight, 20.7% were overweight, and 17.2% were obese. The mean value of body fat percentage was 18.46%, and 16.1% of the boys with ASD had higher than normal fat tissue.

There is a high prevalence of overweight and obesity among Polish boys with autism.

Prevalence and trends of underweight in European children and adolescents: a systematic review and meta-analysis

PURPOSE

This study aimed at providing prevalence trend estimates of underweight among children and adolescents in Europe from 2000 to 2017.

METHODS

MEDLINE, Web of Science, Scopus and CINAHL were searched from their inception up to March 2020. Moreover, searches were conducted on health institutions' websites to identify studies not published in scientific journals. Underweight was defined according to the body mass index (BMI) cut-offs proposed by the International Obesity Task Force (IOTF) and the World Health Organization (WHO) definition criteria. The Mantel-Haenszel method was used to compute the pooled prevalence estimates whenever there was no evidence of heterogeneity; otherwise, the DerSimonian and Laird random-effects method was used. Subgroup analyses by sex, age range (2-13 and 14-18 years old), study year (2000-2006 and 2007-2017), country and European region were conducted.

RESULTS

A total of 49 studies with data from 323,420 children and adolescents aged 2 to 18 years, from 26 countries were included. From 2000 to 2017, according to the IOTF criteria, the prevalence of underweight showed an increasing trend in Eastern, Northern and Southern Europe, where the underweight prevalence ranged from 9.1 to 12.0%, from 4.1 to 6.8%, and from 5.8 to 6.7%, respectively. In Western Europe, the prevalence of underweight tended to decrease, from 14.0 to 11.8%. No significant differences were found by sex or age range.

CONCLUSION

The prevalence of underweight is considerable (overall, around 8-9%), particularly in Eastern Europe, and follows a slight upward trend during the past decade.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017056924.