When You Eat May Be As Important As What You Eat

By Jane Farrell

When you eat may be just as important to heart health as what you eat, according to researchers from San Diego State University and the Salk Institute for Biological Studies.

The researchers, whose findings were published in the journal Science, found that by limiting the time span during which fruit flies could eat, they could prevent aging- and diet-related heart problems.

Previous research has found that people who tend to eat later in the day and into the night have a higher chance of developing heart disease than people who cut off their food consumption earlier, according to a news release from SDSU.

“So what’s happening when people eat late?” asked Girish Melkani, Ph.D., a biologist at SDSU whose research focuses on cardiovascular physiology. “They’re not changing their diet, just the time.”

In their study, the experts looked at whether changing daily eating patterns could affect their heart health. Fruit flies are frequently used to identify the genetic basis of human disease, including heart disease.

In the experiments, a group of 2-week-old fruit flies had a standard diet of cornmeal and was allowed to feed throughout the day. Another group got access to the food for only 12 hours a day.

After three weeks, the researchers found that flies on the 12-hour time-restricted feeding schedule slept better, didn’t gain as much weight and had far healthier hearts than their counterparts, even though they ate similar amounts of food. The researchers observed the same results after five weeks.

Additionally, another set of experiments showed that flies of all ages became healthier when put on a time-restricted diet. The life span of a fruit fly is about 60 days.

“Even if you introduce time-restricted feeding very late, you still have some benefit,” Melkani said.

The researchers said that the results reinforced the fact that the daily eating pattern has a profound effect on the body. But they cautioned that the research cannot yet be extrapolated to humans.

Melkani is optimistic that the results could one day translate into cardiac- and obesity-related health benefits for humans.

“Time-restricted feeding would not require people to drastically change their lifestyles, just the times of day they eat,” Melkani said. “The take-home message then would be to cut down on the late-night snacks.”