There are people who think a light breakfast is the healthiest choice, and there are those who assume that any breakfast will do. Most health experts agree the most important thing is to eat upon waking to kick-start metabolism.

According to a new study from the University of Alabama at Birmingham, there may be a better way to start the morning. Published in the “International Journal of Obesity,” the study suggests the type of food one eats in the morning can make a difference in how the body digests fat and carbohydrates the rest of the day.

The research showed that the mice fed on high-fat diets after waking were able to metabolize both fat and carbohydrates more efficiently throughout the day. Mice fed on high-carbohydrate breakfasts and high fat toward the end of the day (which mimics the eating habits of most people), were not able to metabolize the fat or carbohydrates as readily and experienced weight gain.

Molly Bray, lead author of the study and professor of epidemiology at the University of Alabama at Birmingham School of Public Health, said researchers discovered the enzymes needed to break down fats were at the highest levels shortly after the mice awoke.

“We had already hypothesized that the animals who ate fat upon waking versus the ones who had fat right before they went to sleep would probably have a better outcome,” Bray said. “But we were surprised at how different the metabolism was.”

The mice were fed twice a day, four hours apart, to mimic the way humans eat, she said. They were divided into two groups: one ate a high-fat breakfast with the most caloric intake during the first meal, and the other had a high-carbohydrate meal that  was divided evenly in calories between the meals.

The animals in the two groups ate exactly the same number of calories. The fat in the mice feed came from lard and soybean oil, which, Bray said,  are not considered to be the healthiest kinds of fats.

“So this is what’s cool about this finding,” she said. “It wasn’t one animal got less calories because of the way they ate. What the biggest surprise to us was the way metabolism seemed to really be set at the beginning of the day by what the animals ate upon waking.”

Bray explained that normally mammals use stored fat for energy production during the periods of rest between meals.

The mice given more fat were actively metabolizing both fats and carbohydrates “really, really efficiently,” she said.  However, the mice given high-carbohydrate meals at the beginning of the day kept metabolizing the carbohydrates consumed, not stored fat—even when they were given a high-fat meal at the end of the day.  In the published study, this is referred to as developing a “fixed” metabolism.

“We have evidence that they’re storing fat again because enzymes that are active for storing fat are active at that time of day,” Bray said.

Dawn Jackson Blatner, a registered dietician and spokesperson for the American Dietetic Association, said so much information comes out about nutrition that it’s important to look at all available research.

“Any time you read one story, you can’t make it change your mind,” Blatner said. “At the end of the day, [you should] add it to the body of evidence.”

She also said the study will not change the eating advice she gives to her patients.

“It’s important to keep a balance of carbohydrates, fats and protein for every meal,” Blatner said. “After that, it’s personal preference.”

According to Blatner, breakfast—what she called the “prevention meal” because it helped prevent overeating later in the day—should be well-balanced, such as a combination of oatmeal with produce and a fat like nuts. One egg with turkey bacon, a piece of toast and a piece of fruit would also be acceptable, she said.

Blatner did agree with the emphasis put on eating a breakfast. This first meal helps stimulate the body as well as the mind,  she said.

“It reminds us, are people even eating breakfast?” Blatner asked. “They should, even it’s a grab-and-go.”

Bray warned against jumping to conclusions that all high fat breakfasts are good for the body.

As an example of jumping to conclusions, she cited newspapers in Great Britain using her study to justify a typical English breakfast, which includes much fried food and equals about 800 calories, of which 60 percent come from fat. Currently, 45 percent of calories coming from fat is considered a high fat meal.

However, it is possible to have a high fat, low calorie breakfast, something that is important to tell college students who “love any excuse to chow down,” Bray said.

“I know if you have two eggs that are prepared without oil and butter, a piece of toast with butter on it, and a glass of orange juice, that is 45 percent of calories from fat and 310 calories,” she said. “Even if you add two pieces of bacon to that, it’s 410 calories and 56 percent fat. It’s high in fat, but it’s not a full English breakfast.”

Jessica Marie, a wellness lifestyle coach and founder of Complete Health Education and Wellness Chicago, said it’s important to remember the difference between healthy, monounsaturated fats and the unhealthy, saturated fats.

“I would never ask a human to consume lard and soybean oil,” Marie said. “I think there’s definitely something to be said about healthy fats and what they do for the body.”

Healthy fats, like those that come from nuts and seeds, are proven to be helpful for absorbing other fats and nutrients.

“I absolutely agree [with Bray’s study],” Marie said. “It’s an old saying that you should eat like a king for breakfast, lunch like a prince and dinner like a pauper.”

The next step, Bray said, is to set up a study in humans, which she is in the planning stages of now. The human study will not aim to be a weight loss study because starting with an overweight subject might influence the outcome. She may test mice with high-fat first meals to see if the effect on metabolism could be further enhanced.

Bray said the most important thing to take away from the study is that more people need to consider changing their eating habits around. Eating high-fat, high-calorie food at night can be harmful to your health.

“It makes sense,” Marie said. “You’re more active through the day, you’re using your fuel. You’re not going to put gas in your car if you’re not going anywhere. It’s the same thing with the body.”