The order of your morning routine could impact your weight loss—or gain—a new study reports.

by Lisa Freedman

The premise: Breakfast is billed as the most important meal of the day—but you may want to hold off on eating it until after your daily workout. Researchers in Belgium set up a six-week study to determine if the order of men’s morning routines would make a difference in terms of weight loss and other health aspects. “We hypothesized that training in the fasted state would be a better strategy to improve fat metabolism,” says the study’s lead author Karen Van Proeyen, Ph.D. “However, we were rather surprised that almost all measured parameters were more beneficially affected following a training program before breakfast, compared with a similar training session after breakfast.”

The set-up: The researchers recruited 28 healthy, active men and tweaked their daily diets to include 50 percent more fat and 30 percent more calories (to enhance the effect). The men were then broken into three groups. The first group endured no exercise at all, while the other two groups were both given grueling morning exercise routines. Four times a week, they ran and cycled at intense levels. However, of those two groups, one worked out after a carbohydrate-rich breakfast and drank sports drinks throughout their workout. The other group drank only water and ate breakfast after hitting the gym.

The results: The group that didn’t exercise at all gained an average of more than six pounds (we’re surprised it wasn’t more!). They also developed unhealthy conditions that are often precursors of diabetes including an insulin resistance. The men who ate breakfast before exercising also gained weight (although only about half as much as the first group) and similar cautionary diabetes signs. The group that exercised before breakfast gained almost no weight and showed no signs of insulin resistance. They also burned the extra dietary fat more efficiently.

The takeaway: Exercise routines in this study were very intense 60- to 90-minute sessions. Yet the researchers have said even less intense workouts could have similar results. The old something-is-better-than-nothing way of thinking!

“I recommend exercising before breakfast, of course,” says Van Proeyen. But she can’t recommend an ideal breakfast menu: “Based on our findings we cannot say what the best breakfast is. However, a healthy, well-balanced fiber-rich breakfast—mainly consisting of carbohydrates—is the most optimal breakfast to maintain a good health in normal fit individuals.”

We wanted to know if this trick would work with lunchtime workouts too. Turns out, it doesn’t. “Our subjects always performed the exercise after a 10- to 12-hour overnight fast, which is likely the most convenient way to stimulate fat oxidation.” The time between breakfast and lunch is only about 4 to 6 hours and that’s not enough time to maximize fat oxidation before the workout. Moral of the story: Set your alarm earlier each morning. Get your daily run out of the way, eat breakfast at your desk and enjoy a long, gym-free lunch break.