Researchers at the University of Bath in England have found that working out before eating breakfast might be better for overall health in the long run.
Though the correlation between meal timing and performance isn’t new knowledge—athletes have long utilized connections between the two—it hasn’t progressed much farther than simple facts. For example, concepts such as eating before a workout to raise blood sugar and allow the body to utilize the sugar as fuel, and fasting before a moderate workout to force your body to rely on stored carbohydrates and fat reservoirs are common practices.
However, studies looking at the correlation between exercise and eating have mainly focused on athletes and athletic performance, not the everyday person trying to better their general health. Until now, as the University of Bath studied average people and their fat cells.
The study looked at 10 overweight, sedentary, but otherwise healthy men with lifestyles representative of the everyday person. Before the men embarked on any exercise, the researchers noted the fitness and resting metabolic rates of each man, also taking blood and fat tissue samples.
On two separate mornings, the men walked at a moderate pace—a pace that should alert the body to rely mainly on fat reservoirs as fuel—on a treadmill for an hour. One morning, the men skipped breakfast. The other morning, they ate a large, 600 calorie breakfast supplied by the scientists about two hours before the exercise.
As expected, the men displayed a lower blood sugar and burned more fat when exercising after fasting. When exercising after the large breakfast, the men burned less fat, but more calories.
However, the discoveries didn’t stop there, as what the scientists found deep within the fat cells might have been the most consequential finding. Genes within the fat cells—those that produce proteins that can improve blood sugar and insulin level regulation and are therefore associated with improved metabolic health—were much more active when the men fasted before a workout.
“If we just think of this in evolutionary terms,” said Dr. Dylan Thompson, director of health research at the university and senior author of the study. “Our ancestors would have had to expend a great deal of energy through physical activity in order to hunt and gather food. So, it would be perfectly normal for the exercise to come first, and the food to follow.”
As the study was very short term, it cannot fully predict whether these small, cellular-level changes will necessarily translate into improved long-term health. But, it shows that fasting before a workout might help with improving general health for the average person—something that wasn’t commonly considered before.
Photo: with wind, CC-BY
Emma Korstanje is a freelance journalist based out of Athens, GA.