Identifying developmental trajectories of body mass index in childhood using latent class growth (mixture) modelling: associations with dietary, sedentary and physical activity behaviors: a longitudinal study

Table 2 Characteristics of the study population

Variables of interest [%] or [mean (SD)]	BMI trajectories			P-value^a
Variables of interest [%] or [mean (SD)]	Increasing (N = 197)	Decreasing (N = 416)	Total sample (N = 613)	P-value^a
Gender % male	54.8	48.1	50.2
SES
low	18.2	9.3	12.1	**
middle	26.6	20.3	22.3	**
high	55.2	70.4	65.6	**
Ethnicity – % non-western	14.4	5.8	8.5	**
BMI
2006	15.8 (1.5)	15.5 (1.2)	5.6 (1.3)
2009	17.1 (2.4)	15.4 (1.6)	16.0 (2.0)	**
2012	19.8 (2.6)	16.6 (1.6)	17.6 (2.5)	**
Waist circumference
2006	53.6 (4.2)	53.3 (5.8)	53.4 (5.4)
2009	61.6 (7.0)	57.3 (4.0)	58.7 (5.5)	**
2012	71.8 (8.1)	62.8 (5.1)	65.7 (7.5)	**
Weight status child (%)
Thinness
2006	9.6	10.8	10.4	*
2009	5.0	17.9	13.8	**
2012	0.0	15.6	10.6	**
Healthy weight
2006	81.1	82.7	82.4	*
2009	77.3	77.3	77.3	**
2012	73.1	82.1	79.6	**
Overweight (including obesity)
2006	8.7	6.5	7.2	*
2009	17.6	4.8	8.9	**
2012	26.9	1.7	9.8	**
Weight status parent
BMI mother (% overweight)
2006	46.0	20.7	29.6	**
2012	40.7	25.3	30.2	**
BMI father (% overweight)
2006	51.4	46.6	48.1
2012	58.2	45.3	49.4	*

Abbreviations: BMI body mass index (calculated as weight in kilograms divided by height in metres squared), SDS standard deviation scores, SES socioeconomic status, SD standard deviation
^aP-values determined using X² test (categorical variables or T-test (continuous variables): * p < 0.05 for difference between trajectories; **p < 0.001 for difference between trajectories

ISSN: 1471-2458