Table 1.

Sample characteristics, NHANES 1988–1994 & 1999–2016 (n=13,669)

	n	%a
Age at survey
50–54 years	3012	28.4
55–59 years	2330	21.9
60–64 years	2938	17.9
65–69 years	2196	14.0
70–74 years	1948	11.0
75–79 years	1245	6.9
Gender
Female	5706	43.3
Male	7963	56.7
Race/ethnicity
Non-Hispanic White	6549	78.2
Non-Hispanic Black	3054	9.5
Hispanic	3428	8.4
Non-Hispanic Other	638	3.8
Educationb
Less than high school	5444	26.1
High school/equivalent	2812	22.1
Some college	2858	24.8
College or higher	2555	27.0
Smoking statusc
Never	6344	46.8
Former	3537	26.5
Current	3788	26.6
Weight change categoryd
Normal-normal	3634	28.3
Normal-overweight	4191	30.0
Normal-obese	1575	10.6
Overweight-normal	241	1.6
Overweight-overweight	1587	12.0
Overweight-obese	1592	11.6
Obese-normal	30	0.2
Obese-overweight	126	0.8
Obese-obese	693	4.9
Type of weight changee
Weight loss	397	2.5
Weight maintenance	5914	45.3
Weight gain	7358	52.2
Incident arthritis conditionsf	3603	25.8

^aPercentages are sample weighted using NHANES examination weights. Counts are unweighted.

^bEducation was reported at the time of the NHANES survey.

^cSmoking status was reported from the midlife weight measure (10 years prior to survey).

^dWeight was recorded at age 25 and 10 years prior to survey to determine weight change between young adulthood and midlife.

^eWeight loss includes overweight-normal, obese-normal, and obese-overweight. Weight maintenance includes normal-normal, overweight-overweight, and obese-obese. Weight gain includes normal-overweight, normal-obese, and overweight-obese.

^fIncident arthritis conditions reflects the number of new arthritis conditions that occurred over the 10-years of follow-up from the recalled midlife weight measure to the time of survey.