Table 2.

RRs of breast cancer in relation to energy intake, BMI, recreational physical activity, and height

CasesPerson-yearsRR (95% CI)
Age-adjusted modelMultivariate model 1*Multivariate model 2
Energy intake (kcal/day)
    Q1 (<1,316)16634,1841.01.01.0
    Q2 (1,316-1,657)19834,6621.18 (0.96-1.45)1.14 (0.92-1.40)1.14 (0.93-1.40)
    Q3 (1,658-2,083)17935,1561.05 (0.85-1.30)0.98 (0.79-1.21)0.97 (0.78-1.20)
    Q4 (≥2,084)22134,6521.33 (1.09-1.63)1.25 (1.02-1.53)1.23 (1.01-1.51)
    Ptrend0.0140.0640.085
BMI (kg/m2)
    ≤22.413927,6941.01.01.0
    22.5-24.917731,2801.13 (0.91-1.41)1.20 (0.96-1.51)1.20 (0.96-1.50)
    25.0-27.416829,7911.12 (0.90-1.40)1.24 (0.99-1.56)1.22 (0.97-1.54)
    27.5-29.911418,5541.22 (0.95-1.56)1.42 (1.11-1.83)1.39 (1.08-1.79)
    ≥30.016631,3351.07 (0.85-1.34)1.35 (1.06-1.70)1.29 (1.01-1.64)
    Ptrend0.6730.0140.042
Recreational physical activity (h/wk)
    011320,6231.01.01.0§
    <112925,0850.95 (0.74-1.22)0.89 (0.69-1.15)0.91 (0.70-1.17)
    19516,5821.05 (0.80-1.38)0.96 (0.73-1.26)0.98 (0.74-1.28)
    213223,6461.02 (0.79-1.31)0.90 (0.70-1.16)0.93 (0.72-1.20)
    315123,4801.17 (0.92-1.50)1.02 (0.79-1.30)1.06 (0.82-1.36)
    ≥414429,2380.90 (0.70-1.15)0.78 (0.61-0.99)0.81 (0.63-1.05)
    Ptrend0.8510.1530.302
Height (m)
    <1.5816535,5861.01.01.0
    ≥1.58, <1.6322541,7761.17 (0.96-1.43)1.16 (0.95-1.43)1.16 (0.94-1.42)
    ≥1.63, <1.6822137,1621.30 (1.06-1.59)1.28 (1.04-1.58)1.28 (1.04-1.58)
    ≥1.6815324,1301.40 (1.12-1.74)1.33 (1.06-1.68)1.33 (1.05-1.67)
    Ptrend0.0020.0110.012
  • * Multivariate model 1 adjusted for study center, race (White, Black, Hispanic, Asian, Pacific Islander, American Indian/Alaskan Native), height (continuous), family history of breast cancer (yes or no), history of benign breast disease (yes or no), age at menarche (≤11, 12-13, 14-15, ≥16 y), age at first birth (≤19, 20-24, 25-29, ≥30 y, or nulliparous), parity (0, 1, 2, 3, 4, ≥5 live births), age at menopause (<40, 40-44, 45-49, 50-54, ≥55 y), menopausal hormone therapy (never used, 1-5 y of use, 6-9 y of use, ≥10 y of use), and education (≤11 y, 12 y, or high school equivalent; post-high school; college graduate; or postgraduate).

  • Additionally adjusted for BMI (continuous) and physical activity (all categories included in questionnaire).

  • Additionally adjusted for energy intake (continuous) and physical activity (all categories included in questionnaire).

  • § Additionally adjusted for energy intake (continuous) and BMI (continuous).

  • Additionally adjusted for energy intake (continuous), BMI (continuous), and physical activity (all categories included in questionnaire).