Regression calibration equations from regression of log-calibrated biomarker on log total sugars intake and log total sugars density assessed by FFQ, 4DFR, and three 24HRs among NPAAS (2007–2009) participants (primary study, n = 384; reliability study, n = 78)
| Total sugars intake, g/d | Total sugars density, g/1,000 kcal | |||||
|---|---|---|---|---|---|---|
| Variable | FFQ | 4DFR | Avg. of three 24HR | FFQ | 4DFR | Avg. of three 24HR |
| Intercept | 3.51 (2.50)a | 2.72 (2.50) | 4.63 (2.45) | 0.49 (2.53) | 0.49 (2.51) | 0.64 (2.49) |
| Log self-reported intake | 0.23 (0.08) | 0.30 (0.10) | 0.26 (0.10) | 0.44 (0.13) | 0.36 (0.13) | 0.52 (0.14) |
| Log age | 0.17 (0.52) | 0.25 (0.53) | −0.02 (0.52) | 0.77 (0.53) | 0.85 (0.54) | 0.73 (0.53) |
| Log BMI | −0.11 (0.20) | −0.07 (0.20) | −0.19 (0.19) | −0.37 (0.20) | −0.38 (0.20) | −0.46 (0.20) |
| Smoking status (current) | −0.64 (0.24) | −0.63 (0.24) | −0.59 (0.24) | −0.56 (0.24) | −0.62 (0.25) | −0.57 (0.24) |
| Education | ||||||
| <High school graduate | 0.55 (0.23) | 0.53 (0.23) | 0.51 (0.22) | 0.64 (0.24) | 0.65 (0.24) | 0.41 (0.24) |
| High school graduate | 0.30 (0.14) | 0.29 (0.14) | 0.23 (0.14) | 0.43 (0.15) | 0.44 (0.15) | 0.36 (0.14) |
| Some college | 0.16 (0.09) | 0.16 (0.09) | 0.13 (0.09) | 0.18 (0.09) | 0.19 (0.09) | 0.16 (0.09) |
| College graduate | 0 | 0 | 0 | 0 | 0 | 0 |
| Physical activity | ||||||
| Square-root METs | 0.04 (0.02) | 0.04 (0.02) | — | |||
| For self-reported intake only | ||||||
| R2 | 0.01 | 0.02 | 0.02 | 0.03 | 0.02 | 0.04 |
| Adjustedb R2 | 0.05 | 0.06 | 0.06 | 0.10 | 0.07 | 0.18 |
| Multiple | ||||||
| R2 | 0.06 | 0.06 | 0.04 | 0.09 | 0.09 | 0.10 |
| Adjustedb R2 | 0.18 | 0.17 | 0.16 | 0.34 | 0.29 | 0.40 |
NOTE: Calibrated using the measurement error parameters generated from the feeding study (17). Regression calibration models automatically included self-reported intake, log age, and log BMI as covariates: additional covariates were chosen by backward selection (P = 0.1) from the following covariates: square root physical activity (METs/wk), smoking status (current, former/never), supplement use (yes, no), race (black, white, Hispanic, other), education (<high school graduate, high school graduate, some college, college graduate), annual income (<$20,000, $20,000–$49,999, ≥$50,000), and percentage of meals eaten at home (<75, 75–94, >94).
Abbreviation: METs, metabolic equivalents.