Women who consumed a higher proportion of their daily calories later in the evening were more likely to be at greater risk for cardiovascular disease than women who did not, according to preliminary research to be presented at the American Heart Association's Scientific Sessions 2019 -- November 16-18 in Philadelphia.

Researchers assessed the cardiovascular health of 112 women (average age 33, 44% Hispanic) using the American Heart Association's Life's Simple 7® measures at the beginning of the study and one year later. Life's Simple 7 represents the risk factors that people can improve through lifestyle changes to help achieve ideal cardiovascular health and include not smoking, being physically active, eating healthy foods and controlling body weight, along with measuring cholesterol, blood pressure and blood sugar levels. A heart health score based on meeting the Life's Simple 7 was computed.

Study participants kept electronic food diaries by computer or cell phone to report what, how much and when they ate for one week at the beginning of the study and for one week 12 months later. Data from the food diary completed by each woman was used to determine the relationship between heart health and the timing of when they ate.

Researchers found:

While most study participants consumed some food after 6 p.m., those who consumed a higher proportion of their daily calories after this time had poorer heart health.

With every 1% increase in calories consumed after 6 p.m., heart health declined.

Specifically, women who consumed more of their calories after 6 p.m. were more likely to have higher blood pressure, higher body mass index and poorer long-term control of blood sugar.

Similar findings occurred with every 1% increase in calories consumed after 8 p.m.

The impact on blood pressure was more pronounced in Hispanic women who consumed most of their calories in the evening and persisted even after adjusting for age and socioeconomic status.

"So far, lifestyle approaches to prevent heart disease have focused on what we eat and how much we eat," said lead study author Nour Makarem, Ph.D., an associate research scientist at Columbia University's Vagelos College of Physicians and Surgeons in New York. "These preliminary results indicate that intentional eating that is mindful of the timing and proportion of calories in evening meals may represent a simple, modifiable behavior that can help lower heart disease risk."

The results should be confirmed in a larger sample and in other populations, said Makarem who is a member of the American Heart Association's Council on Epidemiology and Prevention Early Career Committee.

The American Heart Association funded the study through its Go Red For Women Strategically Focused Research Network initiative.

Kristin Newby, M.D., chair of the oversight advisory committee for the Go Red for Women Strategically Focused Research Network, said this type of research is important to help women of all ages better understand and manage their health risks.

"I think it's an important study, it's foundational more than definitive at this point, but I think it provides some really interesting insights into an aspect of nutrition and how it relates to cardiovascular risk factors that we really haven't thought about before," said Newby, professor of medicine and cardiology at Duke University in Durham, North Carolina. "It is never too early to start thinking about your heart health whether you're 20 or 30 or 40 or moving into the 60s and 70s. If you're healthy now or if you have heart disease, you can always do more. That goes along with being heart smart and heart healthy."