Writing in the Journal of the Academy of Nutrition and Dietetics, nutritional interventions targeting energy density as well as other dietary approaches can reduce the cancer burden, researchers suggested.
The findings add to the literature that discuss how the ratio of energy to food weight, otherwise known as dietary energy density (DED), contributes to cancer risk.
Much coverage establishes a proven link between obesity and certain types of cancer. A high intake of dietary components such as saturated fat and a high glycaemic load, among others, are considered a reliable indicator of weight and waist circumference gain.
However, according to lead investigator Dr Cynthia Thomson, professor of Health Promotion Sciences at the University of Arizona, the findings “suggest that weight management alone may not protect against obesity-related cancers should women favour a diet pattern indicative of high energy density."
PHE calorie cutting crusade
Diet is thought to play a significant role in cancer risk. Current research shows that an estimated 30% of cancers could be prevented through nutritional modifications.
Just this morning, the UK announced plans to target foods with a high calorie count as it updated the country’s childhood obesity plan, which previously focused on sugar reduction.
Public Health England (PHE) will now consider evidence on children’s calorie consumption, focusing on cutting calorie count in high-DED foods such ready meals, pizzas, burgers, savoury snacks and sandwiches.
Led by Dr Thomson, researchers drew on data detailing 90,000 postmenopausal women aged 50 to 79 years.
Their eating habits were self-reported using a food frequency questionnaire and medical records were inspected for any obesity-related cancers during the follow-up period.
The team found that women who consumed a diet higher in DED were 10% more likely to develop an obesity-related cancer, independent of body mass index.
Additional findings revealed that the increased risk appeared limited to women who were of a normal weight at enrolment in the study
“The demonstrated effect in normal-weight women in relation to risk for obesity-related cancers is novel and contrary to our hypothesis," said Dr Thomson.
"Among normal-weight women, higher DED may be a contributing factor for obesity-related cancers," she added.
"Importantly, DED is a modifiable risk factor. Nutrition interventions targeting energy density as well as other diet-related cancer preventive approaches are warranted to reduce cancer burden among postmenopausal women."
The weight of evidence
A number of notable studies have assessed the role of DED in weight management.
A study of more than 89,000 Europeans suggested a role of DED in relation to gains in central adiposity among adults of normal body weight at the start of the study.
In addition, a systematic review suggested a consistent relationship between DED and excess adiposity and adult weight gain, but not BMI or central obesity.
“In our study, DED was associated with higher BMI and waist circumference,” the study explained.
“However, risk was demonstrated in women with normal BMI. Among normal-weight women, those in the highest and lowest DED quintiles had mean waist circumference of 75.8 and 74.0 centimetres (cm), respectively.”
The study highlighted the significance of this finding, pointing out that few normal-weight participants (less than 2%) became obese during follow-up of the main study period (around 10 years).
The study argued that weight gain alone could not explain the elevated cancer risk shown in the results.
“Body composition data that could inform on adiposity and the role of lean mass are limited in numbers within women, thereby precluding robust evaluation in relation to DED and obesity-related cancer risk.”
Source: Journal of the Academy of Nutrition and Dietetics
Published online ahead of print: doi.org/10.1016/j.jand.2017.06.010
“Association between Dietary Energy Density and Obesity-Associated Cancer: Results from the Women’s Health Initiative.”
Authors: Cynthia Thomson et al.