Table 4.

Multivariate relative risks of breast cancer in relation to energy intake and BMI and to energy intake and recreational physical activity, considered concurrently

Quartile of energy intake (kcal/d)BMI*, RR (95% CI)
<25 kg/m225-29 kg/m2≥ 30 kg/m2
Q1 (<1,316)1.01.20 (0.85-1.68)1.10 (0.71-1.68)
Q2 (1,316-1,657)1.16 (0.85-1.58)1.38 (1.00-1.91)1.13 (0.74-1.71)
Q3 (1,658-2,083)0.93 (0.68-1.29)1.11 (0.79-1.55)1.25 (0.85-1.83)
Q4 (≥2,084)1.20 (0.87-1.65)1.37 (0.99-1.88)1.60 (1.13-2.25)
Pinteraction = 0.56
Quartile of energy intake (kcal/d)Recreational physical activity*, RR (95% CI)
≥4 h/wk<4 h/wk
Q1 (<1,316)1.01.44 (0.94-2.21)
Q2 (1,316-1,657)1.30 (0.78-2.15)1.60 (1.05-2.45)
Q3 (1,658-2,083)1.13 (0.67-1.91)1.37 (0.89-2.10)
Q4 (≥2,084)1.53 (0.94-2.48)1.74 (1.14-2.65)
Pinteraction = 0.68
  • * 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).