Postmeno older women 55–69 years Case = 660 self- reported WT change 18–62 years
Stable WT (ref) (<5% change between ages 18 and 62 years) and small gain (at least one gain between 5 and 10%) Large cycle (at least one gain 10% and at least one loss 10%) Small cycle(at least one gain ≥5% but <10% and at least one loss ≥ 5% but <10%) Large gain (at least one gain ≥10%) Weight loss maintenance (a > 10% weight loss with 5% maintenance of reduced value) Others (all other unspecified weight change patterns) Cox proportional hazard regression with multivariate adjustment for baseline values of age, waist/hip ratio, BMI, BMI2, smoking status (never, former, and current), pack years of cigarettes, education (<high school, high school, and >high school), physical activity (low, medium, and high), alcohol, marital status (yes/no), and hormone replacement (never, former, and current)
Stable W T(ref) versus large cycle 0.83 (0.60–1.14), small cycle 0.86 (0.58–1.27), large gain 1.29 (1.02–1.63), weight loss maintenance 0.81 (0.50–1.30), and others 1.01 (0.80–1.28) Large gainers were at significant risk of BC (versus stable weight)
First study Large sample size Weight variability was defined as () the root-mean-square-error (RMSE) around the slope of weight on age and () categorical measures of weight change
Case-Control 50–79 years old Massachusetts, New Hampshire, Wisconsin
Postmeno invasive BC Case = 5031 Cont. = 5255
Weight cycling: at least 1 cycle loss of at least 20 pounds and regain back of at least half during a year Conditional logistic regression on age and state, adjusted for parity, age at first full-term pregnancy, family history of breast cancer, recent alcohol consumption, education, and age at menopause
≥1 cycle versus no cycles OR = 1.0 (0.9–1.1) No association
~18.6% cases and ~17% controls were weight cyclers
Case-Control 20–98 years old Long Island Breast CSP: 1996-1997
Postmeno diganosed: first primary in situ or invasive Cases = 990 Cont. = 1,006
Weight cycling as switching from “low” to “high” status and back at 4 time-points: 20, 30, 50, and 1 y before ref/diagnosis: “high” and “low” versus control medium weight (kg) Unconditional logistic regression adjusted for age at reference day (diagnosis), number of pregnancies, lactation status, nulliparity, history of breast cancer in a mother, sister, or daughter, and history of benign breast disease
OR = 2.11 (1.00–4.44)
Twofold increase in risk versus mainlining the “low” status
