Associations of Body Mass Index with Sexual Risk-Taking and Injection Drug Use among US High School Students

Table 1

Prevalence of BMI categories and HIV/STD-related risk behaviors, by sex among high school students, United States, 2005–2011.

Subgroups	Female students, 𝑁=30217			Male sudents, 𝑁=29377			Chi-square
	𝑛	%	(95% CI)	𝑁	%	(95% CI)	𝑃 value
BMI category
Normal	20336	73.3	(72.3–74.2)	17825	65.8	(64.8–66.8)	𝑃=0.0000
Underweight	603	2.2	(2.0–2.5)	750	2.7	(2.4–3.0)
Overweight	4614	15.3	(14.7–15.9)	4421	15.7	(15.1–16.3)
Obese	2892	9.3	(8.7–9.8)	4678	15.8	(15.0–16.7)
HIV-related behaviors
Sexual experience^a	28051	45.7	(44.3–47.2)	26661	48.2	(46.3–50.0)	𝑃=0.0023
Current sexual activity^b	28014	35.0	(33.8–36.2)	26539	33.3	(32.0–34.7)	𝑃=0.0176
Multiple sex partners^c	10406	30.7	(29.4–32.0)	9934	45.3	(43.7–47.0)	𝑃=0.0000
No condom use^d	10284	45.5	(44.1–46.9)	9744	31.5	(30.0–33.1)	𝑃=0.0000
Injection drug use^e	10245	2.7	(2.4–3.2)	9791	5.6	(5.0–6.3)	𝑃=0.0000

BMI: body mass index = weight [kg]/height [m]² (based on self-reported height and weight, using age- and sex-specific percentiles from growth charts developed by Centers for Disease Control and Prevention); normal = 5th percentile ≤ BMI < 85th percentile; underweight = BMI < 5th percentile; overweight = 85th percentile ≤ BMI < 95th percentile; and obese = BMI ≥ 95th percentile. HIV: human immunodeficiency virus. STD: sexually transmitted disease. CI: confidence interval.
^aEver had sexual intercourse.
^bHad sexual intercourse during the 3 months before the survey.
^cHad sexual intercourse with four or more persons during their lifetime (among students who were currently sexually active).
^dDid not use a condom during last sexual intercourse (among students who were currently sexually active).
^eEver used a needle to inject any illegal drug into their body (among students who were currently sexually active).