Table 2.

Power analysis for detecting differences in various scenarios.

Scenarios - Ability to detect:	Est. mean (SD)	Policy n	Comparison n	Power
1) 0.5 BMI unit longitudinal change difference over the course of 3 time points, with projected sample	22.3 BMI units (4.5)*	658	717	0.97
2) 0.5 BMI unit longitudinal change difference over 3 time points if final sample is 30% smaller due to unexpected attrition	22.3 BMI units (4.5)*	461	502	0.90
3) 0.5 BMI unit longitudinal change difference over 3 time points if the larger intervention s fails to implement policy	22.3 BMI units (4.5)*	197	1178	0.77
4) 0.5 BMI unit longitudinal change difference over 3 time points among girls	22.3 BMI units (4.5)*	329	358	0.78
5) 1.0 BMI unit longitudinal change difference among low-income student population over the course of 3 time points	22.3 BMI units (4.5)*	164	179	0.97
6) 0.2 breakfasts per week longitudinal change difference over 3 time points.	3.2 per week (1.5)*	658	717	0.96
7) 0.15 sugar sweetened beverages per day longitudinal change difference over 3 time points	1.4 per day (1.1)*	658	717	0.96
8) 0.3 breakfasts per week longitudinal change difference over 3 time points among low-income participants	3.2 per week (1.5)*	164	179	0.79
9) 0.25 sugar sweetened beverages per day longitudinal change difference over 3 time points, among low income	1.4 per day (1.1)*	93	143	0.88

^*Mean overall values and standard deviations from Project EAT study, unpublished

^{^}Mean values and standard deviations from Redline et al. (31)