A cross sectional research on the height, weight and body mass index of children aged 5-6 years in Latvia and its secular changes during the last century.

Aim: To determine the main anthropometric parameters and their changes during the 20th and early 21st centuries for children aged 5-6 and to analyze the nutritional level of the population based on percentage.

Methods: 536 healthy Latvian 5 and 6 year old children were randomly selected and a cross sectional survey was carried out. To collect anthropometric data, the height and weight of each child was measured and BMI calculated. The Kolmogorov-Smirnov Goodness-of-Fit test was used to assess the distribution of data; it was concluded, that the data for both boys and girls in both analyzed age groups fits a normal distribution. Using a t-test statistical tool, the results were compared to our previous study (1998/1999) and to the most significant national anthropometric investigations of the 20th century.

Results: During the last decade, the mean values of height and weight (for both boys and girls) have increased in both age groups. The mean BMI value increase for 6 year old boys and girls was not statistically significant (p > 0.05). The BMI mean values for 5 year old boys and girls have decreased (p < 0.05). In both age groups the highest percentage of children are of normal weight. In the past 10 years the proportion of 5 year old underweight children has increased, but the proportion of overweight children has decreased percentage-wise. In all analyzed age groups a little tendency towards increase of the percentage of obese children can be observed. From 1929 to 2007/2009, the overall mean values of height and weight have increased, but BMI mean values have decreased.

Conclusion: Positive secular changes were observed in body height and weight during the past decade (p < 0.01) and century. The increase in BMI at the beginning of the 21st century in comparison to the end of the 20th century may possibly be facilitated by the increased occurrence of overweight, obesity and related diseases in Latvian children. However, the number of underweight children has increased in the last decade as well.