Background:Regular physical activity and adequate nutrition have favourable influence on the bone status, while body structure and function could be altered with lifestyle. The main
aim of this study was to analyse habitual physical activity, body parameters, macro- and micronutrient intake and ultrasound bone characteristics in prepubertal children.
Methods:Hungarian children aged between 10 to 12 years (N=123; 59 girls and 64 boys)
provided physical activity, anthropometric, diet, and bone data. All girls were premenarcheal. Children from twelve different schools in various regions - the capital, large towns, small towns and
villages - were included. Objective level of habitual physical activity was measured with accelerometer (Actigraph GT3X+). Diet was evaluated by three-day, 24-hour food recall. Calcaneal quantitative
ultrasound (QUS) parameters were registered with Sonost 3000 bone densitometer. The analysis contained speed of sound (SOS, m/s), broadband ultrasound attenuation (BUA, dB/MHz), bone quantity index
(BQI=αSOS+βBUA). Differences between subgroups were tested by Student’s t-test. Correlation patterns of the variables for total sample and subgroups were analyzed (p<0.05).
Nutrition and anthropometric variables did not differ by gender. Values of Broadband Ultrasound Attenuation (BUA) were significantly higher in boys. Girls spent significantly more time being
sedentary, and boys had more light, moderate, vigorous, and moderate to vigorous physical activity (MVPA) levels. On average, the children accumulated more than twice the suggested amount of current
public health guidelines for MVPA: 159.23±36.90 vs. 133.44±44.28 min. QUS parameters correlated significantly with vigorous physical activity in boys, and with age, height, weight, fat percentage and
BMI for both sexes. There was no significant relationship between nutrition and QUS; however, inadequate vitamin K intake correlated with less favourable bone parameters.
Changes in the ultrasound bone characteristics among 10 to12 year old children mainly depended on the amount of intense physical activity and age and age-dependent anthropometric variables; nutrition
could not be decisive.