Table 4.

Predicted probabilities of weight status and weight-related behaviors, incorporating both weekend night-school night sleep duration difference and sleep timing difference into the same model

		Weekend Night-School Night Sleep Duration Differenceb
	n	<−0.5 hours	≥−0.5 to <0.5 hours	≥0.5 to <1.5 hours	≥1.5 to <2.5 hours	≥2.5 hours	pa (df=4)
Weight status
BMI z-score ≥85th percentiled	224	15.8%	16.2%	11.9%	12.1%	19.1%	0.72
BMI z-score ≥95th percentiled,e	233	6.9%	11.1%	6.2%	3.6%	15.7%	0.13
Eating behaviors
Eat breakfast 5 days/week	225	37.2%	59.1%	64.3%	56.1%	48.1%	0.31
Eat supper with family 5–7 days a week	228	61.9%	53.2%	49.8%	52.6%	55.0%	0.96
Food consumption
Fruit or vegetables daily	228	73.1%	70.1%	62.5%	72.7%	70.9%	0.76
Fast food weekly	227	68.7%	71.5%	65.5%	72.3%	62.3%	0.80
Physical activity
Active 6–7 days/week	227	58.5%	51.4%	56.3%	66.5%	31.1%	0.02
Moderate-strenuous activity ≥7 hours/week	227	74.8%	44.2%	47.4%	50.9%	33.2%	0.11
Beverage consumption (mean times/day)
Sugar-sweetened beverages	228	1.5	1.4	1.2	1.5	1.2	0.81
Caffeinated beverages	228	0.5	0.3	0.5	0.8	0.6	0.34
		Weekend Night-School Night Sleep Timing Differenceb
	n	<1 hours	≥1 to <2 hours	≥2 to <3 hours	≥3 hours		pa (df=3)
Weight status
BMI z-score ≥85th percentiled	224	15.4%	17.8%	10.3%	16.8%		0.48
BMI z-score ≥95th percentiled,e	233	9.2%	8.3%	3.9%	12.1%		0.28
Eating behaviors
Eat breakfast 5 days/week	225	57.2%	46.7%	53.1%	55.0%		0.72
Eat supper with family 5–7 days a week	228	61.1%	56.9%	60.0%	39.8%		0.27
Food consumption
Fruit or vegetables daily	228	73.5%	66.9%	72.8%	66.4%		0.75
Fast food weekly	227	61.4%	67.2%	72.3%	71.3%		0.64
Physical activity
Active 6–7 days/week	227	52.8%	41.6%	51.9%	64.2%		0.25
Moderate-strenuous activity ≥7 hours/week	227	52.9%	39.1%	50.5%	59.3%		0.24
Beverage consumption (mean times/day)
Sugar-sweetened beverages	228	1.4	1.3	1.3	1.4		0.84
Caffeinated beverages	228	0.5	0.6	0.4	0.8		0.49

BMI = body mass index; df = degrees of freedom

Bold text indicates p ≤0.05

^aRegression models include both the sleep duration and sleep timing predictor variables. Regression models adjusted for age, sex, free or reduced-price lunch eligibility, and racial/ethnic categorization (non-Hispanic white vs Hispanic or not white); school ID included as a random effect due to students nested within schools.

^bWeekend night-school night sleep duration difference refers to the difference in weekend night and school night sleep duration (weekend night duration – school night duration), so that a positive difference corresponds to longer duration on weekend nights compared to school nights and a negative difference corresponds to a shorter duration on weekend nights.

^cWeekend night-school night sleep timing difference refers to the difference in weekend night and school night sleep timing (weekend night midpoint – school night midpoint), so that a positive difference corresponds to later midpoint on weekend nights than school nights and a negative difference corresponds to an earlier midpoint on weekend nights

^dObjective height/weight data used when available.

^eModel with 95^th percentile BMI outcome not adjusted for free/reduced lunch eligibility due to convergence issues.