Table 3.

Model BMI trajectories by sex over life course

	Model BMI trajectory by sex with 95% CI
# of obs	60,531
# of groups	14,810
Fixed effect
Mean BMI (intercept) at age 20	19.218***	[19.070–19.365]
Rate of change by one unit of age	0.162 ***	[0.153–0.172]
Changing in rate by one unit of age	-0.002***	[-0.002-(-0.002)]
Sex-(ref group Male)	0.121	[-.074–0.315]
Interaction sex-age	0.067***	[0.054–0.079]
Interaction sex—age square	-0.001***	[-0.001-(-0.0003)]
Random effect
Level I—within person
variance residual	2.750	[2.706–2.794]
Levell II—between person
variance initial BMI (intercept)	9.275	[8.823–9.751]
variance rate of change (slope)	0.013	[0.013–0.014]
cov(intercept & slope)	-0.073	[-0.087-(-0.059)]
p-value random effect
Goodness of fit
Log likelihood	-143,188.790
AIC	286,397.600
BIC	286,487.700

^*** p-value significant < 0.001