TABLE 1.
Means and Standard Deviations of Key Variables by Baseline BMI Classification
| Variable | Range | Total (N = 4,574) | Underweight (N = 137) | Normal (N = 1,904) | Overweight (N = 1,681) | Obese (N = 852) |
|---|---|---|---|---|---|---|
| BMI Wave 1 | ||||||
| Underweight W1 | 0−1 | .03 | ||||
| Normal weight W1 | 0−1 | .42 | ||||
| Overweight W1 | 0−1 | .37 | ||||
| Obese W1 | 0−1 | .19 | ||||
| Life course obesity | ||||||
| Obese age 25 | 0−1 | .04 | ||||
| Obesity duration | 1−46 | 9.59 (10.00) | ||||
| (age adjusted, ln) | −.05−.09 | .03 (.02) | ||||
| Morbidity | ||||||
| Diabetes | .07 | .07 | .05 | .08*** | .09*** | |
| Heart disease | .10 | .11 | .08 | .09 | .13*** | |
| Hypertension | .29 | .25 | .21 | .30*** | .46*** | |
| Status characteristics | ||||||
| Age | 41−77 | 56.73 (9.38) | 58.47 (9.76)* | 56.07 (9.56) | 57.03 (9.27)* | 57.31 (9.05)*** |
| Black | 0−1 | .13 | .20** | .11 | .12 | .20*** |
| Female | 0−1 | .53 | .55 | .55 | .44*** | .64*** |
| Education | 0−7 | 3.37 (1.59) | 3.07 (1.58)*** | 3.57 (1.58) | 3.37 (1.57)*** | 2.99 (1.55)*** |
| Income | 1−12 | 7.31 (2.89) | 5.97 (3.24)*** | 7.61 (2.82) | 7.41 (2.84)* | 6.64 (2.93)*** |
| Lives alone | 0−1 | .15 | .21** | .13 | .14 | .18** |
| Health care resources | ||||||
| Medicaid | 0−1 | .04 | .07* | .04 | .03 | .06* |
| Private insurance | 0−1 | .84 | .77* | .85 | .86 | .80*** |
| Regular physician | 0−1 | .87 | .85 | .87 | .85 | .88 |
| Lifestyle | 0−1 | |||||
| Heavy drinker | 0−1 | .12 | .15 | .13 | .12 | .09** |
| Smoker | 0−1 | .39 | .63*** | .45 | .37*** | .28*** |
| Sedentary lifestyle | 0−1 | .09 | .15*** | .07 | .09 | .13*** |
| Place of residence | ||||||
| Rural | 0−1 | .42 | .55** | .40 | .40 | .45* |
| Northeast | 0−1 | .24 | .19 | .22 | .25 | .24 |
| South | 0−1 | .24 | .19 | .23 | .25 | .25 |
| West | 0−1 | .26 | .41 | .29 | .25* | .23** |
| Midwest | 0−1 | .26 | .21*** | .26 | .25 | .27 |
| Hospitalization | ||||||
| Stays per year | 0−4.86 | .17 (.26) | .22 (.28)** | .16 (.25) | .18 (.26)** | .20 (.25)*** |
| Average length of stay | .5−307.5 | 9.95 (11.59) | 10.26 (10.27) | 9.40 (10.58) | 9.99 (13.21) | 10.96 (10.29)** |
*
p < .05
**
p < .01
***
p < .001 (two-tailed tests)
Source: National Health and Nutrition Examination Survey I, Epidemiological Follow-up Study.
Notes: BMI = body mass index. Standard deviations in parentheses. Reference group for significance tests is “normal” BMI category. Mean differences between continuous variables are compared with t-tests, and differences between binary variables are compared with χ2 tests.