Racial differences in weight perception among Black and White women diagnosed with breast cancer.

Purpose: Black women are more likely than White women to have obesity, and obesity is associated with worse breast cancer prognosis. Weight perception, however, has not been studied as a potential mediator of obesity disparities in women with breast cancer. In this study, we sought to describe racial differences and the association of lifestyle factors with weight perception.

Methods: In this cross-sectional study design, Black and White women with a new primary breast cancer were surveyed about socio-demographics, weight perception, diet, and exercise habits. Height and weight were measured at enrollment. We classified women with a BMI ≥ 25 kg/m or waist circumference ≥ 88 cm who reported that they were "about the right weight" as under-perceivers. Chi-square and t tests were used to assess study variables (e.g., race, physical activity) associated with under-perception of weight. Logistic regression models were fit to evaluate for racial differences in under-perception while controlling for other covariates.

Results: Of 1,197 women with newly diagnosed breast cancer, the average age was 58 years, and 909 (75.9%) were White. Nine hundred eighteen (77%) had stage I cancer, 1,035 (87%) had estrogen receptor positive cancer, and 795 (66%) were privately insured at time of diagnosis. Seven hundred eighty-nine (66%) women had abdominal obesity (waist circumference ≥ 88 cm), while 366 (31%) women had a BMI ≥ 25 kg/m. Overall, 24% of women were under-perceivers. Compared to White women, Black women with WC ≥ 88 cm more frequently under-perceived their weight (24% vs. 14% p < 0.0001) were more obese with BMI > 30 kg/m (51% vs. 23%, p < 0.0001) and had lower physical activity (22% vs. 77%, p < 0.0001). After controlling for age, education, and stage, Black women remained more likely to under-perceive their weight relative to White women for those with BMI ≥ 25 kg/m (OR: 2.64; 95% CI: 1.4-4.6) or waist circumference ≥ 88 cm (OR: 2.89; 95% CI: 1.8-4.5). With respect to lifestyle factors, among women with BMI ≥ 25 kg/m, those who met physical activity guidelines were less likely to under-perceive their weight compared to those who did not meet physical activity guidelines (OR: 0.37; 95% CI: 0.2-0.6), regardless of race.

Conclusions: We found racial differences in weight perception and identified social determinants and lifestyle factors such as lower education and physical inactivity that influenced under-perception of weight among newly diagnosed breast cancer patients.

Implications For Cancer Survivors: Since obesity is associated with worse breast cancer outcomes, identifying optimal modifiable factors to intervene upon to support weight management among breast cancer survivors is clinically important. Breast cancer patients' perceptions about their weight provide insight that may inform lifestyle behavior interventions to reduce obesity during survivorship care.