Thomson CA, et al. – This study investigated the link between baseline dietary energy density (DED) and incident obesity–associated cancers in the Women’s Health Initiative. Findings indicated a possible contribution of higher DED to obesity–related cancers, especially among normal–weight postmenopausal women, and potential of it serving as a modifiable behavior for dietary interventions to reduce obesity–associated cancer risk.

Methods

• This is a prospective cohort study of clinical trial and observational study participants.
• This study included postmenopausal women aged 50 to 79 years (N=92,295) enrolled in the observational study or the calcium and vitamin D trial and hormone replacement therapy trials of the Women’s Health Initiative.
• Main outcome measures were: incident, medical record-adjudicated, obesity-related cancers during follow-up and, exposure variable was DED (kilocalories per gram for the total diet) from self-reported dietary intake at baseline using a food frequency questionnaire.
• Researchers assessed the links between DED and each incident cancer, or any obesity-related cancer, using competing-risks regression models, with death as a competing risk.
• They also generated body mass index-stratified models to investigate body mass index as a potential modifying factor.

Results

• Findings demonstrated that DED was associated with higher body mass index (28.9±6.0 vs 26.3±4.9) and waist circumference (89.3±14.2 vs 82.4±12.4 cm) for DED quintiles 5 vs 1, respectively.
• Researchers observed that DED was associated with a 10% increased risk of any obesity-related cancer (subhazard ratio_{Q5 vs Q1}: 1.1, 95% CI 1.03 to 1.2; P=0.004).
• In addition, they noted that this increased risk appeared limited to women who were normal weight at enrollment.