Muscle & Fitness/Hers

Timing is everything: if you think the fastest way to a lean body is to eat less and work out more, read on and learn about the surprising new research

Timing is everything: if you think the fastest way to a lean body is to eat less and work out more, read on and learn about the surprising new research

Martica Heaner

WHEN THE TORCH IS LIT IN Athens this summer, lots of athletes will be watching the clock–and not just because they don’t want to miss their events. New research showing that when you eat is just as important as what you eat has resulted in several elite athletes changing their eating habits. By concentrating on timing their meals and snacks just right, many of them have now been able to report being leaner, less fatigued and more focused. “We’ve found that athletes who match their food intake to their energy expenditure at any given hour not only are less likely to ‘bonk,’ they are more mentally alert and have better muscle-to-fat composition than athletes who eat erratically,” confirms Dan Benardot, PhD, RD, one of a group of nutritionists and exercise physiologists at Georgia State University (Atlanta) at the forefront of studying the effects of meal timing on athletic performance.

While the athletic diet has been analyzed to death, looking at the timing of eating is new–and it’s changing the way competitors eat, as well as how active, recreational exercisers eat. Here’s what you need to know to develop your own optimal eating schedule.


Common wisdom has it that if the amount of calories you consume equals the amount of calories you burn, you’ll stay in energy balance, and neither gain nor lose weight. That’s been the assumption, anyway. But Benardot and his colleagues’ research essentially throws that traditional energy equation out the window. The researchers found that when and how often their athletes took in calories throughout the day made a big difference in each person’s day-end energy balance.

One study, for instance, showed that female gymnasts and runners who didn’t eat or snack for three hours or longer had the highest body fat percentages–even if they weren’t consuming more calories than they were burning. Furthermore, the longer the gap between eating times, the higher the body fat, especially if they exercised during those noneating periods. Keep in mind that these were competitive athletes training hours every day–they weren’t overweight. But when compared to fellow runners and gymnasts, those who ate fewer and bigger meals retained higher levels of body fat.

Perhaps even more surprising, the same study showed that those who ate less than their energy needs–traditionally the recipe for weight loss-weren’t losing weight. The runners, for example, ate an average of 200 to 400 fewer daily calories than they were burning, and some of these athletes reached points during the day when, because they were performing intense exercise without having eaten recently, they dipped into a caloric deficit of up to 1,100 calories for a few hours. But these exercisers were not losing weight, as you’d expect; in fact, they were among the “fattest” of the bunch. The reason, suspects Benardot, is that when deprived of food, even for just a few hours, the body desperately clings to any calorie it gets.


To elaborate on the calorie-clinging theory, Benardot explains that if you expend lots of extra energy when the body is underfed, the fuel the body needs in the form of liver and muscle glycogen (stored carbohydrate) is nowhere to be found. To cope, the body takes the irregular step of converting proteins in muscle tissue into blood glucose that it can use for energy. In other words, exercise on a long-empty stomach and you’ll lose and weaken muscle.

And there’s more. Since the body senses that food is in short supply, it shifts into starvation mode, which means that the next time you eat, there will be a larger-than-normal insulin response in an effort to capture the calories coming in. That, and the fact that the fat-storing enzyme, lipoprotein lipase, revs up higher than usual, results in a greater number of the newly ingested calories being tucked away as fat. “Now,” the body thinks in its infinite yet out-of-date wisdom, “I’ll be prepared for future times of famine.”

One other factor that may determine why some people who go several hours without meals or snacks tend to have more body fat is that infrequent eating impairs appetite regulation, and that can lead to bingeing. Moreover, those who don’t snack tend to play catch-up by eating oversize meals. “When you gorge after long periods without eating, the body is overloaded and becomes even more efficient at storing the extra calories as fat,” explains John Ivy, PhD, a physiologist at the University of Texas and co-author of Nutrient Timing (Basic Health, 2004).


Benardot’s research demonstrates that it’s key not to hit a calorie deficit or a calorie surplus greater than 300. Of course, short of living in a laboratory, there’s no surefire way to know your exact energy-balance status at any given time. But you can avoid oversize deficits and surpluses by eating small- to moderate-size meals every three to four hours. And if you’re going to work out in intense or long exercise sessions, eat more before and during to compensate. “If you ate a few hours earlier but are about to take a spin class followed by a weight-lifting session, you need enough fuel during that time to avoid diving into energy deficit,” says Karen Dolins, EdD, RD, a nutrition professor at Columbia University in New York City and a nutritionist who follows these guidelines with her clients. “So burning around 700 calories doing a 90-minute workout means you need about 400 before and during so that you don’t accrue a deficit of more than 300 calories.”

For many women, this means paying particular attention to breakfast–a meal that’s commonly skipped by morning exercisers, some of whom believe it’s a way to get the body to dip into its fat stores. “You will burn a higher percentage of fat, but you won’t burn more calories, which is what really affects weight,” says Benardot.

Some athletes are also under the impression that hunger pangs before practice mean that the body will be able to divert all of its energy to the workout instead of to digestion. But while eating too much too close to intense training can slow down a practice, so can not eating enough. If your stomach is sensitive to more than just the smallest pre-workout snack, try to replenish your calories every 15 to 20 minutes with quick-absorbing carbs, like those found in sports drinks.

As you consider your food timing, keep in mind that one of the most crucial times to eat is right after an intense workout. Within the first 45 minutes or so postexercise–what physiologist Ivy calls the “metabolic window”–the enzymes that replenish glycogen in the muscles are at their highest. Plus, insulin, which rebuilds protein stores, is also at peak levels. So eating a carb-and-protein mix (peanut butter sandwich, yogurt with fruit, or nuts) right after training will increase your muscles’ ability to rebuild themselves, replenish your glycogen stores and reduce the amount of fat that your body stores.

Missing this metabolic window can be bad news. “If you delay refueling, you’ll slow glycogen replenishment by 50 percent and protein repair by 80 percent,” says Ivy.


Will you eat more if you eat more often? In a word, no. In fact, stabilizing your body with a constant fuel supply will likely help better regulate your appetite. “We found that giving athletes 750 calories’ worth of snacks did not increase their overall food intake, because they automatically–and subconsciously–reduced the size of their meals,” says Benardot.

Plus, numerous studies have shown that people who eat more often binge less because they aren’t as hungry when mealtime comes around. Many athletes agree. “The best thing about eating around six meals and snacks a day is that you never become so famished that you eat enough to go into a ‘food coma,'” says Jessi Stensland, a triathlete who’s an alternate on the 2004 U.S. Olympic team. “When I eat something every three hours. I feel light and ready for anything.”


COPYRIGHT 2004 Weider Publications

COPYRIGHT 2004 Gale Group