Table 3.

Actual BMI vs self-reported BMI by actual body type

NIH BMI category	Actual BMI, kg/m 2a	Self-reported BMI, kg/m 2a	Difference, kg/m 2b	P value c
All patients (N = 508)
Underweight	17.3 ± 0.7	17.4 ± 0.8	−0.1	.70
Normal	22.5 ± 1.6	22.2 ± 1.6	0.3	<.001
Overweight	27.4 ± 1.4	26.7 ± 1.6	0.7	<.001
Obese	35.1 ± 5.1	33.8 ± 4.9	1.3d	<.001
Women (n = 257)
Underweight	17.3 ± 0.7	17.4 ± 0.8	−0.1	.70
Normal	22.3 ± 1.6	22.0 ± 1.8	0.3	.001
Overweight	27.2 ± 1.4	26.5 ± 1.6	0.7	<.001
Obese	35.2 ± 4.4	34.1 ± 4.1	1.1d	<.001
Men (n = 251)
Underweight	NA	NA	NA	NA
Normal	23.0 ± 1.5	22.7 ± 1.3	0.3	.002
Overweight	27.6 ± 1.4	26.8 ± 1.5	0.7	<.001
Obese	35.0 ± 5.6	33.5 ± 5.4	1.5d	<.001

Abbreviations: BMI body mass index, NA not applicable, NIH National Institutes of Health.

^aValues shown are mean ± SD.

^bAnalysis of variance for trend of differences.

^cMatched pairs t test comparing actual BMI vs self-reported BMI by actual body type.

^d P < .001 using analysis of variance for trend of differences.