smart phone taking pic of food
Study participants will take photos of their meals using a smartphone app.

University of Hawaiʻi Cancer Center researchers have received a five-year, $5.6 million grant to help reduce intra-abdominal fat, overall body fat and to improve cancer-related biomarkers and gut microbiome functions for high-risk ethnic groups in Hawaiʻi. The National Institutes of Health award will be used to conduct a 24-week randomized trial among overweight individuals comparing intermittent energy restriction (IER) to daily energy restriction (DER) interventions.

Study with local ethnic groups

To further study the benefits of IER, UH Cancer Center researchers and principal investigators Loïc Le Marchand, Carol Boushey and Unhee Lim, will conduct the study using an IER protocol or DER protocol combined with a Mediterranean dietary pattern among 260 middle-aged Oʻahu residents of Asian, Native Hawaiian/Pacific Island or white ethnicity.

“People with large amounts of fat inside their abdomen are at a particularly high risk of diabetes, heart disease and some types of cancers, including breast cancer,” said Le Marchand. “We believe such individuals will lose enough of this ‘visceral fat’ to reduce their risk of disease by following a diet with a reduced caloric intake during two consecutive days of the week for six months—which may be easier and more effective than a daily reduction in calories.”

The intervention will be delivered through customized consultations with a research dietitian. The research dietitians will monitor dietary compliance using photos taken by the participants of their meals using a smartphone app.

“We have done extensive work demonstrating that following a healthy dietary pattern, such as the Healthy Eating Index or the Mediterranean dietary pattern, rich in whole grains and fruits and vegetables, leads to reductions in cancer risk,” said Boushey. “This randomized study will add unique temporal data, and we are so lucky our Hawaiʻi community will have a chance to potentially benefit from the study.”

IER versus DER interventions

In previous studies, UH Cancer Center researchers have identified striking ethnic and racial disparities in their predisposition to accumulate intra-abdominal fat and in the strength of the association between obesity and cancer risk. To reduce these disparities, the researchers investigated the use of an IER dietary intervention to decrease intra-abdominal fat and improve gut microbiome composition.

Researchers have found that IER interventions are more easily maintained and have a greater beneficial effect compared to DER. IER interventions require an individual to restrict calories only a few days out of the week, whereas many weight-control programs use DER interventions, which require an individual to restrict calories daily.

UH researchers hope to better understand how IER combined with a healthy diet may be able to lower cancer-related risk and inform future dissemination research to reduce cancer risk in various high-risk ethnic groups in Hawaiʻi and elsewhere.

This research is an example of UH Mānoa’s goal of Excellence in Research: Advancing the Research and Creative Work Enterprise (PDF), one of four goals identified in the 2015–25 Strategic Plan (PDF), updated in December 2020.