PHILADELPHIA — People who prefer eating dinner later at night may be putting their weight and their heart at risk, a new study finds.
Researchers at the University of Pennsylvania say that consuming meals past 7 p.m. may lead to weight gain, along with higher insulin, cholesterol, and triglyceride levels — putting a person at higher risk for heart disease and diabetes.
The study authors examined nine healthy adults who underwent two separate diet regimens: one in which three meals and two snacks were eaten between 8 a.m. and 7 p.m., and the other in which the same quantity of food was eaten between noon and 11 p.m. Each regimen lasted for eight weeks.
There was a two-week cool down period between the two experiments, which allowed the first condition to affect the second to a lesser extent. The sleeping pattern of participants was held constant throughout the study, between 11 p.m. and 9 a.m.
To measure results, participants had their metabolism checked and blood drawn at four points during the study: prior to the first diet regimen, after the first diet regimen, after the two-week gap, and after the second diet regimen.
The researchers found that eating dinner later increased the weight of participants, while also raising their respiratory quotient, in turn leading participants to metabolize fewer lipids and more carbs.
In addition, many hormones and health markers increased to unhealthy levels, including insulin and cholesterol, and an increased risk for heart disease and diabetes was found.
“We know from our sleep loss studies that when you’re sleep deprived, it negatively affects weight and metabolism in part due to late-night eating, but now these early findings, which control for sleep, give a more comprehensive picture of the benefits of eating earlier in the day,” says lead author Dr. Namni Goel, a research associate professor of psychology, in a university press release. “Eating later can promote a negative profile of weight, energy, and hormone markers—such as higher glucose and insulin, which are implicated in diabetes, and cholesterol and triglycerides, which are linked with cardiovascular problems and other health conditions.””
The study also suggests that hormonal factors allow an individual who eats earlier in the day to feel full for longer.
Previous studies had explored similar angles, but this study was much longer in duration, and controlled for a number of variables, including sleep-wake cycles, exercise, and macronutrient intake.
“While lifestyle change is never easy, these findings suggest that eating earlier in the day may be worth the effort to help prevent these detrimental chronic health effects,” says Kelly Allison, the study’s senior author.
The study’s findings will be presented at SLEEP 2017, the 31st Annual Meeting of the Associated Professional Sleep Societies LLC in early June.