Table 2 .

Mean annual weight change and proportion of participants by weight-change categories according to sample characteristics

	N	Mean annual weight change (kg)	p Value*	Annual weight-change category			p Value†
				Loss (%) n=7685 (17%)	Maintenance (%) n=26 922 (60%)	Gain (%) n=10 430 (23%)
Sex
Male	20 911	0.21	0.019	18	60	22	<0.001
Female	24 126	0.27		16	60	24
Age (years)
45–54	15 031	0.41	<0.001	14	57	28	<0.001
55–64	15 207	0.26		16	60	24
65–74	9619	0.14		18	63	19
75–84	4549	−0.07		24	61	15
85 plus	631	−0.26		32	56	13
Education
No school cert	3857	0.14	0.016	22	54	25	<0.001
School cert	13 635	0.23		18	58	24
Trade/cert/dip	15 059	0.28		16	60	23
University degree	12 486	0.24		16	63	22
Physical activity tertile
Low	11 896	0.19	0.025	19	56	25	<0.001
Moderate	15 918	0.25		17	60	23
High	16 751	0.27		15	62	22
Physical impairment
None/minor	34 813	0.25	0.080	16	62	23	<0.001
Moderate	3662	0.21		22	53	25
Severe	1848	0.13		26	46	28
Smoking status
Never	26 315	0.21	<0.001	16	62	22	<0.001
Past	15 953	0.25		18	58	24
Current	2634	0.50		18	49	33

*p Value of analysis of variance tests. †p Value of χ² tests.

Physical impairment was measured using the Medical Outcomes Score-Physical Functioning (MOS-PF), which is equivalent to items from the physical functioning scale of the SF-36 health survey (none/minor=score of 75–100; moderate=score of 50–74; and severe=score of <50). No weight change is defined as an annual weight change of between −1 and 1 kg. Weight loss is defined as >−1 kg annual weight change. Weight gain is defined as >1 kg weight change.