TABLE 4.

Hierarchical multiple regression analysis for changes in dietary magnesium intake from 6th to 8th grade in control and intervention schools¹

Outcome	Grade	Variables	R 2	b	β	SEb	t	P
Changes in dietary magnesium intake—intervention	6th and 8th	BMI percentile	0.14	−0.30	−0.07	0.14	−2.11	0.03*
		Glucose		−0.86	−0.05	0.47	−1.82	0.78
		Insulin		−1.02	−0.08	0.41	2.50	0.54
		Dietary calcium		0.11	0.37	0.01	12.75	<0.01*
		Total energy intake		0.001	0.10	0.01	6.40	<0.01*
		Constant		−9.25
		SEE		132.88
Changes in dietary magnesium intake—control	6th and 8th**	BMI percentile	0.12	−0.36	−0.08	0.14	−2.63	0.01*
		Glucose		−0.10	−0.01	0.46	−0.21	0.83
		Insulin		−0.21	−0.02	0.40	−0.53	0.60
		Dietary calcium		0.11	0.33	0.01	11.89	<0.01*
		Total energy intake		0.001	0.15	0.00	9.43	<0.01*
		Constant		−1.41
		SEE		138.22

¹ n = 2181. *Correlation is significant at the 0.05 level (2-tailed). **Subtract 8th grade from 6th grade. Β, standardized β coefficient; b, unstandardized β coefficient; glucose, plasma glucose concentrations; insulin, plasma insulin concentrations; R², variability of the model explained; SE_b, SE for the unstandardized β.