Table 3 Model BMI trajectories by sex over life course

# 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