Eggnog, butter cookies, potato latkes, honey-baked ham—such yummy but fattening fare is everywhere during the holidays. And though we know that extra exercise could blast away the extra calories, few of us can spare the time to work out more.

It’s no mystery why the average person puts on about a pound of weight between Thanksgiving and New Year’s, according to research.

Now, one pound may not seem like such a big deal. But when it happens year after year, those pounds add up…and up.

That’s why you’ll want to know about a simple strategy that helps prevent weight gain during times when your diet is unusually high in calories and fat, such as during December’s day-after-day feasting. This trick won’t even take up any extra time. You only need to rearrange your daily schedule a bit—so that you exercise at the time when your body naturally burns more fat. And that magic hour is…just before breakfast.


This very valuable advice comes from a study that was conducted in Belgium. For six weeks, all of the healthy participants were put on a high-calorie, high-fat diet that included 30% more calories than they usually ate, with half of those calories coming from fat.

One group of participants exercised vigorously (biking and running) for 60 to 90 minutes four times each week after consuming a carbohydrate-rich breakfast…and they drank a carbohydrate beverage during their workouts. A second group followed the identical exercise regimen, but they worked out before breakfast and they drank only water while exercising. (To keep calorie counts identical between both groups, the before-breakfast exercisers ate that same carb-rich meal and consumed that same carbohydrate drink later in the day.) A third group, which served as a control, followed the same diet but did not exercise at all.

Results: After six weeks, the nonexercising control group members had gained an average of nearly seven pounds, while the group that exercised after breakfast gained about three pounds. However, there was no significant weight gain among those who did their exercise before breakfast.

The before-breakfast workout also had other important health benefits. At the start and end of the study, the researchers tested participants’ levels of glucose tolerance and insulin sensitivity —indicators of how well the body is able to use insulin to pull glucose from the bloodstream into the cells for use as energy. Poor glucose tolerance and reduced insulin sensitivity are major risk factors for type 2 diabetes. Again, at the end of the study, the before-breakfast exercisers showed significantly better results on these tests than the nonexercisers and after-breakfast exercisers—and they also had less fat stored in their muscle cells.


I asked the study’s lead author, Karen Van Proeyen, PhD, to explain why the prebreakfast exercise group did so much better than the post-breakfast exercisers even though everyone was following the same poor diet.

She said that during exercise, the body responds to the physical stress by changing the levels of hormones involved in the use of energy, including adrenaline and insulin. Adrenaline stimulates fat-burning, while insulin has the opposite effect. According to Dr. Van Proeyen, when exercise is performed during fasting—e.g., before you’ve eaten anything for the day—adrenaline levels are about two times higher and insulin concentrations are about 10 times lower, as compared with the same exercise performed after eating. This improved ratio between adrenaline and insulin allows the body to burn more fat during the workout.

Bottom line: During festive feasting seasons, set your alarm clock for a little earlier and hit the gym before breakfast. On days when that’s not possible, Dr. Van Proeyen suggested, you can let at least six hours pass between your last meal and your workout—for instance, by eating lunch at noon and then exercising at 6 pm.