When making dinner reservations, should you be fashionably late or go for the early-bird special?

We spend a lot of time dissecting what we eat, but it turns out the timing of our meals may also be important. And when we choose to eat the very last meal of the day especially may matter, nutritionists say.

“For years, we said a calorie is a calorie no matter when you consume it,” dietitian Joy Dubost, a spokeswoman for the Academy of Nutrition and Dietetics, tells the Washington Post. “I don’t know if we can say that anymore, based on the emerging research. The timing of a meal may potentially have an impact.”

Recent studies typically have shown that when calories get consumed later at night, the body tends to store them as fat rather than burn them as energy.

And some studies done with animals found that food is processed by the body in different ways depending on what time of day it's consumed. This might be because of physical activity, hormone levels, changes in body temperature, biochemical reactions and absorption and digestion of food, Steven Shea, director of the Oregon Institute of Occupational Health Sciences at Oregon Health & Science University, tells the Washington Post.

Timing matters

man looking in refrigerator When you eat early, you may look for a late-night snack a few hours later. (Photo: Andrey_Popov/Shutterstock)

There's no "best" time to eat dinner across the board, registered dietitian Angel Planells, a spokesman for the Academy of Nutrition and Dietetics, tells MNN. It depends on when you get up and go to bed, as well as if and when you eat your other meals.

"Breakfast sets you up for success," Planells says. "If you don't eat breakfast, by lunchtime you're starving, and by dinner any healthy eating plans are out the window."

Typically our dinner schedules are dictated by our lives. If you have young children, for example, you're much more likely to eat early. If you work long hours at your job, you may not be able to get around to eating dinner until much later in the evening.

If late dinners are the case, it's especially key to make smart food choices. Eating heavy meals close to bedtime can lead to heartburn and trouble sleeping.

"Avoid having something too rich or heavy," Planells says. "Your body is going to be trying to process it and you wont be able to go to sleep."

On the flip side, eating too early and choosing certain foods can mean you're hungry just a few hours later.

"If we eat early and don't get enough protein or fiber, the potential downside is we're more likely to get a late-night snack, and choose more decadent foods like cookies, cake or other snacks," Planells says.

Dinner timing and weight loss

If you're trying to lose weight, you may want to consider eating dinner very early or making a late lunch your last meal of the day.

In a recent study, researchers found that meal timing has an impact on human metabolism. They studied a small group of people carrying extra weight and found that those who ate their last meal by mid-afternoon had reduced daily hunger swings and increased fat burning at night.

“Eating only during a much smaller window of time than people are typically used to may help with weight loss, specifically by increasing our body’s ability to burn fat and protein,” says Courtney Peterson, Ph.D., who led the study at Pennington Biomedical Research Center. “We found that eating between 8 a.m. and 2 p.m. followed by an 18-hour daily fast burned more fat and kept appetite levels more even throughout the day, in comparison to eating between 8 a.m. and 8 p.m. which is average for Americans.”

Eating early also seems to be the optimal time for blood sugar control, Peterson tells MNN.

"Starting around 3 p.m., blood sugar control is substantially worse than it is in the morning, meaning that if you ate the same meal at 3 p.m. as you did for breakfast, your blood sugar levels would rise higher, despite the fact that you act the same amount of food," she says.

Peterson's research found that eating in a shorter daily window — 8 hours versus 12 hours — and an earlier time both affect metabolism.

"We and others have found that eating in a short time interval seems to boost fat burning," she says. "In general, based on evidence so far, it’s better to eat dinner earlier in the day or to have breakfast and/or lunch be the largest meals of the day."

When in Rome

tapas set on table in Spain A typical dinner in Spain might include tapas, or small bite-sized dishes. (Photo: zarzamora/Shutterstock)

In many places in Europe, dinner is well past sundown. In Spain for example, according to Frommer's, "The chic dining hour, even in one-donkey towns, is 10 or 10:30 p.m. (In well-touristed regions and hardworking Catalonia, you can usually dine at 8 p.m., but you still may find yourself alone in the restaurant.) In most middle-class establishments, people dine around 9:30 p.m."

In Europe and other places where they eat late, being overweight is rarely an issue. That's typically because of what they eat, Planells says.

"The amount of food that they eat in the evening is not heavy and rich. Their traditional big meal is light and more like a snack," he says. "If you decide to eat late at night, you don’t want something rich and heavy. You're looking at protein and fiber and making sure you get that so you feel satisfied."

Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.