PhD defence: Growth and body composition of school-aged children
The influence of a school meal intervention, hormones and season
Stine-Mathilde Dalskov
PhD thesis
The overall aim of the present PhD thesis was to examine factors influencing on or associated with growth and body composition of school-aged children including a dietary school meal intervention, hormones, and season. Results were based on a large school meal study carried out in the school year 2011-2012 among third and fourth graders in 9 Danish schools (834 children enrolled).
Results suggest that provision of ad libitum school meals based on an apparently healthy diet (The New Nordic Diet) may have potentially negative effects on children´s body composition despite overall positive effects on risk markers of cardio metabolic health.
The large study gave a unique possibility for analyzing how hormones are associated with changes in body composition and bone growth. The hormone leptin produced by fat tissue was higher in children with high fat mass, but seemed to prevent weight gain (gain in fat mass index as well as fat-free mass index). However, leptin also seemed to have a negative effect on gain in bone size (height-adjusted bone area).
The hormones insulin-like growth factor 1 and osteocalcin had positive effects on gain in height and bone size, while the hunger stimulating hormone ghrelin seemed to decrease gain in bone size. No associations were found between the hormones adiponectin, insulin and parathyroid hormone and changes in body composition or bone growth.
Substantial seasonal variations in growth and body composition were found, which may have practical implications in relation to analysis of growth data over shorter periods of time, and in planning of strategies to combat obesity.
2015, 166 pages,
ISBN 978 87 7611 860 0
Time
19 March 2015, 13:00
Venue
Festauditoriet 1-01, Bülowsvej 17, 1870 Frederiksberg.
Opponents
Professor Henrik Friis (chair), Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark.
Emeritus Professor Ze’ev Hochberg, Faculty of Medicine, Technion, Israel Institute of Science, Israël.
Professor Jonathan Wells, UCL Institute of Child Health, UK.
Supervisors
Professor Kim Fleischer Michaelsen, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark.
Associate professor Christian Mølgaard, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark.
Associate professor Christian Ritz, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark.