Table 2.

Baseline, 6-month, and 16-month follow-up weight, physical activity, and nutrition-related outcomes of users of the Web-Based Guide to Health intervention

Outcome		Study time pointa	Mean	SD	F	dfb	P-value	Partial-eta squaredc
Body weight inpounds		base	176.98	28.03	29.01	1,194	<.001	.130
		16 mo	172.34	28.01
Nutrition
	Fruit servings/day	base	1.13	0.81	83.34	1,236	<.001	.261
		16 mo	1.66	0.95
	Vegetable servings/day	base	2.97	1.93	55.128	1,236	<.001	.189
		16 mo	3.95	2.36
	Percentage kilocalories from fat	base	36.62	5.86	37.33	1,236	0.00	.14
		16 mo	34.40	6.21
	Percentage kilocalories from sweets	base	14.53	9.32	45.07	1,236	0.00	.16
		16 mo	11.30	8.50
	Kilocalories/day	base	1820.95	700.81	22.36	1,236	0.00	.09
		16 mo	1641.14	510.47
	Family social support	base	2.70	.81	57.193	1,245	<.001	.189
		6 mo	3.07	.83
	Friend social support	base	2.91	.78	29.768	1,245	<.001	.108
		6 mo	3.16	.74
	Self-efficacy for avoiding fat and sugar	base	75.99	17.29	2.875	1,245	.091	.012
		6 mo	77.59	16.81
	Self-efficacy for eating healthy foods	base	73.48	16.80	3.794	1,245	.053	.015
		6 mo	75.59	17.73
	Positive outcome expectations	base	4.32	.61	0.01	1,245	0.95	.00
		6 mo	4.32	.57
	Negative outcome expectations	base	2.90	.73	16.89	1,245	0.00	.06
		6 mo	2.72	.81
	Self-regulation healthy food choices	base	3.11	.82	301.23	1,245	0.00	.55
		6 mo	4.06	.62
	Self-regulation high-fat/high-sugar foods	base	3.01	.75	292.27	1,245	0.00	.54
		6 mo	3.84	.61
	Self-regulation planning and tracking nutrition	base	2.35	.81	376.72	1,245	0.00	.61
		6 mo	3.58	.79
Physical activity
	Steps/day	base	6252.89	1876.34	40.32	1,177	0.00	.19
		16 mo	7741.47	3247.56
	METhours/week walkingd	base	2.82	9.70	45.20	1,177	0.00	.20
		16 mo	12.43	18.02
	Family social support	base	2.49	1.03	19.98	1,245	0.00	.08
		6 mo	2.77	1.01
	Friend social support	base	2.88	.98	8.05	1,245	0.01	.03
		6 mo	3.07	.87
	Self-efficacy	base	64.09	19.24	4.06	1,245	0.05	.02
		6 mo	61.28	22.24
	Positive affective outcome expectations	base	16.24	3.92	0.23	1,245	0.63	.00
		6 mo	16.38	4.57
	Positive physical outcome expectations	base	20.49	4.22	2.33	1,245	0.13	.01
		6 mo	20.05	4.81
	Negative outcome expectations	base	10.61	4.84	0.01	1,245	0.93	.00
		6 mo	10.65	5.13
	Self-regulation goal setting and planning	base	1.98	.76	439.28	1,245	0.00	.64
		6 mo	3.47	.94
	Self-regulation tracking activity	base	1.53	.71	604.49	1,245	0.00	.71
		6 mo	3.65	1.19
	Self-regulation increase enjoyment	base	1.79	.84	387.59	1,245	0.00	.61
		6 mo	3.30	1.04

^a Baseline (base), 6 months (6 mo), or 16 months (16 mo).

^b df: degrees of freedom for F test result.

^c partial-eta squared.

^d MET: metabolic equivalent.