Seasonal variations in growth and body composition of 8-11-y-old Danish children.
BACKGROUND
Earlier studies on seasonality in growth reported the largest height gains during spring and largest body weight gains during autumn. We examined seasonality in height, body weight, BMI, fat mass index (FMI), and fat-free mass index (FFMI) among contemporary Danish 8-11-y olds.


METHODS
A total of 760 children from the OPUS School Meal Study provided >2,200 measurements on height, body weight, and composition between September and June. Average velocities were calculated using change-score analyses based on 3-mo intervals. As a complementary analysis, point velocities derived from estimated growth curves were fitted using semiparametric regression that included covariate adjustment and allowed flexible modeling of the time trend.


RESULTS
Average velocities showed the following trends: height was higher than the average (6.10 cm/y) in January-April. Body weight was below the average (4.02 kg/y) in August-January and above in January-May; BMI (average: 0.49 kg/ m(2)/y) and FFMI (average: 0.17 kg/m(2)/y) showed similar trends. In contrast, FMI was above the average (0.38 kg/m(2)/y) in November-March. Similar trends were seen for point velocities.


CONCLUSIONS
Our findings suggest seasonality in growth and body composition of Danish children. We recovered the well-known height velocity peak during spring time, but unlike earlier studies, we found coincident peaks in body weight, BMI, and FFMI velocities.
Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
Stine-Mathilde
SM
Dalskov
Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
Christian
http://orcid.org/0000-0002-5095-0624
C
Ritz
Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
Anni
A
Larnkjær
Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
Camilla T
CT
Damsgaard
Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
Rikke A
RA
Petersen
Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
Louise B
LB
Sørensen
Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
Mads F
MF
Hjorth
MRC Epidemiology Unit, University of Cambridge School of Clinical Medicine, Cambridge, UK.
Ken K
KK
Ong
Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
Arne
A
Astrup
Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
Christian
C
Mølgaard
Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
Kim F
KF
Michaelsen
D050154:Adiposity; D000367:Age Factors; D001823:Body Composition; D001827:Body Height; D015992:Body Mass Index; D002648:Child; D002657:Child Development; D003718:Denmark; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D016032:Randomized Controlled Trials as Topic; D012621:Seasons; D013997:Time Factors; D015430:Weight Gain