Secular changes in height have been observed in many regions of Poland using cross-sectional data; however, data from four nationally representative surveys conducted from 1955 to 1988 have only been partially analyzed. Dramatic social and economic transitions during this 33 year period provide a unique opportunity to understand changes in growth within this historic context. We analyzed the changes in height of boys, aged 7 to 18 years, from surveys conducted in 1955, 1966, 1978 and 1988. Data for height were converted to Z-scores using the LMS method and the 2000 National Center for Health Statistics reference. In each consecutive survey year, boys at all ages were significantly taller than the same aged boys from the previous survey year, with mean height increases of a 2.35 cm, 3.43 cm and 1.47 cm between 1955-1966, 1966-1978 and 1978-1988, respectively. There were significant declines with age in height Z-scores from 7 to 14 years of age, followed by improvements relative to the reference between 14 and 18 years of age. The decline in Z-scores may be partially explained by an effect of delayed maturation. However, historic context also supports that some birth cohorts likely experienced a more adverse environment during early childhood than did other birth cohorts.

BackgroundAnthropometric data, especially in children, has been widely used to evaluate the effects of socioeconomic conditions on growth and well‐being.ObjectiveThe aim of this analysis is to describe the changes in height, weight and body mass index (BMI) in Polish schoolboys born between 1937 and 1981 from a historic perspective.MethodsData from four nation‐wide cross‐sectional surveys (1955, 1966, 1978, and 1988) were analyzed. Height, weight and BMI were converted to standardized scores using the LMS method applied to the 2000 National Center for Health Statistics growth reference.ResultsIn each consecutive survey year schoolboys (7–18 years) are generally taller and heavier than the same aged boys in the previous survey year. Within survey years, there is a decline with age into puberty in height Z‐scores. The prevalence of obesity is low and underweight appears to have greater relative importance.ConclusionsHistorical context of economic changes supports that adolescents measured within each survey year likely experienced an adverse environment during their first few years of life. This was partly compensated during later growth in selected birth cohorts that were measured over a 10 to 12 year interval. Some, but not all of the age dependant decline in the Z‐scores can be explained as an artifact of the reference.Research support came from Fulbright and the NS Meinig Professorship at Cornell.Grant Funding Source: Research support came from Fulbright and the NS Meinig Professorship at Cornell.

This study examined whether iron deficiency has a negative impact on physical activity (PA) in female Mexican factory workers. Non‐pregnant women (18 to 51 y) working in 4 garment factories in the state of Morelos, Mexico were identified as iron deficient anemic (IDA; N=14), iron deficient without anemia (IDNA; N=14) and normal (N=15). Anemia was defined as Hb<120 g/L and ID was defined by serum ferritin (SF) <16 μg/L. Soluble transferrin receptor (sTfR) combined with SF was used to calculate total body iron (mg/kg) by the method of Cook et al. (2003). An ActiGraph accelerometer was used to measure PA during four 24‐hr periods during the workweek and the 2‐regression model of Crouter et al. (2005) was used to determine the MET level. Dividing the women based on negative and positive body iron stores showed the greatest differences in moderate‐to‐vigorous PA (MVPA, > 3 METs). Compared to women with positive body iron stores (N=15) those with negative body iron (N=28) had 31 fewer min/day (18%) of MVPA, with 16 fewer min/day (23%) observed during the 9‐hr factory shift and 15 fewer min/day (14%) during non‐working hrs. Additionally, when using only Hb and SF to determine iron status, the IDA women were less active than non‐IDA women and IDNA women were less active than non‐IDNA women, however the majority of the difference in MVPA was observed during the non‐working hours. We conclude that ID contributes to reduced MVPA, which has important implications for productivity, earnings, quality of leisure and home‐based activities and obesity risk in this Mexican population.