Growth of urban school children in Malawi

Evidence of an overweight/obesity transition among school-aged children and youth in Sub-Saharan Africa: a systematic review

BACKGROUND

Prevalence of childhood overweight/obesity has increased considerably in recent years. The transition to higher rates of overweight/obesity has been well documented in high income countries; however, consistent or representative data from lower income countries is scarce. It is therefore pertinent to assess if rates of overweight/obesity are also increasing in lower income countries, to inform public health efforts.

OBJECTIVE

This systematic review aimed to investigate the evidence for an overweight/obesity transition occurring in school-aged children and youth in Sub Saharan Africa.

METHODS

Studies were identified by searching the MEDLINE, Embase, Africa Index Medicus, Global Health, Geobase, and EPPI-Centre electronic databases. Studies that used subjective or objective metrics to assess body composition in apparently healthy or population-based samples of children and youth aged 5 to 17 years were included.

RESULTS

A total of 283 articles met the inclusion criteria, and of these, 68 were used for quantitative synthesis. The four regions (West, Central, East, and South) of Sub Saharan Africa were well represented, though only 11 (3.9%) studies were nationally representative. Quantitative synthesis revealed a trend towards increasing proportions of overweight/obesity over time in school-aged children in this region, as well as a persistent problem of underweight. Weighted averages of overweight/obesity and obesity for the entire time period captured were 10.6% and 2.5% respectively. Body composition measures were found to be higher in girls than boys, and higher in urban living and higher socioeconomic status children compared to rural populations or those of lower socioeconomic status.

CONCLUSIONS

This review provides evidence for an overweight/obesity transition in school-aged children in Sub Saharan Africa. The findings of this review serve to describe the region with respect to the growing concern of childhood overweight/obesity, highlight research gaps, and inform interventions.

PROSPERO REGISTRATION NUMBER

CRD42013004399.

Growth in prepubertal Nigerian children is highly dependent on socio-economic status

AIM

To relate height, weight and body mass index (BMI) of prepubertal children in Sagamu, Nigeria, to parental socio-economic class (SEC).

METHODS

Cross-sectional study of 1606 children aged 5-11 years from eight public and eight private primary schools. Height, weight and BMI from 1557 prepubertal children were standardized using two references: US-CDC birth cohorts 1929-1974 and Swedish birth cohort 1974.

RESULTS

Children in private schools were taller and heavier than those in public schools (p < 0.0001). Most children (73.2%) belonged to lower SEC, 17.6% to middle and 9.2% to upper. HeightSDS , weightSDS and BMISDS increased with increasing parental SEC. Upper SEC children were taller and heavier with higher BMIs than those from lower SEC (p < 0.0001). HeightSDS , weightSDS and BMISDS were below '0' in all SEC and gender groups (all p < 0.002). Younger children were taller and heavier than the older (p < 0.0001).

CONCLUSION

Fathers/mothers with higher education/occupation had taller and heavier children with higher BMI than other groups. Children in private schools were taller and heavier than children in public schools. Disparities in parental SEC still constrain optimal child growth in Nigeria: whereas height and weight of children of upper SEC were close to the US-CDC29-74 reference mean, they were still below Swedish74 reference mean representing more optimal growth.

Growth pattern of schoolchildren in Sagamu, Nigeria using the CDC standards and 2007 WHO standards

OBJECTIVE

To compare the median weight, height and body mass index of school children with the 2000 CDC and 2007 WHO reference values.

SETTINGS

Schoolchildren in Sagamu, Nigeria.

DESIGN

Cross-sectional survey.

METHODS

Between November and December, 2008, 1690 school children aged 6 to 16 years from 8 primary schools were surveyed using multi-stage sampling methods. The weight, height and body mass index (BMI) were recorded for each child. The Z-scores of the median anthropometric parameters for each age and sex were determined with the LMS statistical method using the values of L, M and S provided on the CDC and WHO charts.

RESULTS

The weight, height and BMI Z-scores were less than the reference values provided on the CDC and WHO charts but were generally closer to the WHO standards compared to the CDC standards. The median weight, height and BMI for females generally plotted higher on CDC and WHO chart compared to the males. The prevalence of underweight and stunting were relatively lower while the prevalence of overweight and obesity was relatively higher among children aged 6 to 10 years using the WHO references compared to the CDC reference values.

CONCLUSIONS

The WHO references would under-diagnose under-nutrition and over-diagnose overweight/obesity in the population studied.

Anthropometric indices in rural Malawians aged 45–75 years

OBJECTIVE

The aim of this cross-sectional study was to assess anthropometric parameters of rural people aged 45-75 years in the Southern Region of Malawi.

SUBJECTS

97 males and 101 females aged 45-75 years were selected from 10 villages in Balaka district using a stratified cluster sampling method. Most responders were small-scale farmers growing maize and vegetables for household consumption. The anthropometric measurements taken were height, weight, triceps skinfold (TSK) and mid-upper arm circumference (MUAC). The derivatives from anthropometric measurements included body mass index (BMI), mid-upper arm muscle area (MUAMA) and mid-upper arm fat area (MUAFA). Weight status of Malawian subjects was estimated using WHO (1995) categories for BMI values, and height, weight, TSK, MUAC, MUAMA and MUAFA were compared with NHANES reference data for black sample.

RESULTS

Correlation between age of subjects and the anthropometric indices was weak and insignificant. Males were generally taller and lighter than females. All anthropometric indices of Malawian subjects were considerably lower than NHANES medians. However the mean values of height, weight, MUAC and MUAMA of females were closer to the reference values than those of males. It was found that 9.1% of Malawian subjects had mild thinness (BMI 17.0-18.4 kg m(-2)), 13.6% had moderate thinness (BMI 16.0-16.9 kg m(-2)) and 18.2% exhibited severe thinness (BMI<16.0 kg m(-2)). The proportion of thin persons was higher (chi2 = 9.58, n = 1, p<0.01) among males than females (50.0% versus 35.7%).

CONCLUSIONS

This study indicates that undernutrition is a serious problem among rural Malawians aged 45-75 years.

Body height differentiation by season of birth: Girls from Cracow, Poland

Published studies world wide demonstrate that measures of human development and health status vary depending on the month of birth but these patterns are not always consistent and sometimes even conflict. Direct factors related to the birth season that may significantly differentiate morphological and functional traits and mechanisms causing these relations have not been found so far. On the basis of cross-sectional material, gathered in the years 1983 and 2000 by the Department of Anthropology of the Academy of Physical Education in Cracow, two main hypotheses have been verified: (1) average body height differences by month of birth are statistically insignificant, (2) the magnitude of these differences does not change with time. Metric data of 4672 girls aged 5-18 years, born in 1965-1978 and 1982-1995, were used. The total sample was also subdivided into prepubertal (5-9 years) and adolescent (10-18 years) groups. The age of the individuals was calculated to the nearest day and the procedure of standardization on the interpolated values of regional norms was applied. A highly significant relationship between the birth month and average values of height was revealed in preadolescent girls. The results obtained for the entire material proved insignificant. The patterns of the month-of-birth effect on body height for girls born in 60./70. and 80./90. show high similarity, though the effect seems weaker in the latter sample. Winter proved to be the most favorable birth season for later body height.

Childhood malnutrition and growth in a rural area of Western Kenya

An anthropometric survey was carried out on 1,383 school students aged 5-17 years in Suba district (a rural area of western Kenya). Body size and proportion were computed from height, weight, sitting height, arm circumference, and skinfolds. The aim of the study was to evaluate patterns of growth and nutritional status of the Luo population by assessment of the prevalence and trends of malnutrition among children and adolescents. Very few age-groups show significant sex differences for height, body weight, and arm muscle area. However, there are several differences in skinfold thicknesses and arm circumference, always with higher mean values in girls. Analysis of the nutritional status (weight-for-age, height-for-age, and BMI-for-age) shows significant differences among the age-groups in both sexes. Boys present lower Z-scores than girls and there are higher percentages of malnourished subjects (stunted and underweight) among the males. The Luo data were compared with those of other African populations. Their body dimensions, nutritional status, and growth are similar to those of the other sub-Saharan samples. In conclusion, the Luo children are generally undernourished at the older ages: adolescents (11-16 years of age) show the most severe undernutrition and the highest percentages of undernourished subjects. In addition to the higher risk of undernutrition in teenagers, an emerging problem of over-nutrition is evident among the younger age-groups, with a higher prevalence in females. These findings are discussed in light of sexual dimorphism in sensitivity to adverse environmental conditions.

Cross-sectional growth of pastoralist Karimojong and Turkana children

In this study, we compare cross-sectional growth in two Nilotic pastoralist populations, the Turkana and Karimojong of northern East Africa. Until the middle of the 18th century, these two groups constituted one population, and their genetic affinities consequently are assumed to be strong. Known differences in their subsistence practices as well as their recent cultural history allow us to consider the genetic vs. environmental determinants of their growth patterns. Growth in stature of the two groups is remarkably similar, whereas the pattern of ponderal growth varies, particularly in infancy and adolescence. Both groups demonstrate the linear adult physique that is characteristic of savanna-dwelling peoples in East Africa, but the Karimojong are heavier and fatter after early childhood. Linearity of physique is related to narrow skeletal breadth, a trait that emerges early in childhood among the Karimojong and is strongly correlated with weight: this finding supports the climatic hypothesis of human body shape and size. Extreme leanness, determined from body mass index, is correlated with fat stores, which are only weakly correlated with weight, height, or skeletal breadth. Linearity of physique appears to have a substantial genetic component, whereas fatness is hypothesized to relate to differences in subsistence strategies and exposure to environmental and cultural stress.