You Burn Twice as Much Fat Exercising Before Breakfast

Among those who exercise on a regular basis, some choose to work out first thing in the morning before eating and some never go on an empty stomach. Those in the former group may find they have more company soon because the results of a new study show the timing of your meals in relation to exercise can have a “profound and positive” effect on the outcome.

Researchers from the Universities of Bath and Birmingham in England found men who worked out before breakfast burned twice as much fat as those who ate first. The workout before breakfast scenario also yielded better results in the control of blood sugar levels.

The report published in the Journal of Clinical Endocrinology and Metabolism detailed how 30 men classified as obese or overweight were studied over a six-week period. Some exercised before breakfast and some afterward. Their results were compared to a control group that made no changes to their lifestyle.

Scientists wanted to build on evidence from other studies indicating the timing of meals can have an impact on the effectiveness of exercise. They found the additional fat burning was as a result of lower insulin levels from the participants having fasted overnight. That meant their bodies used more fat from their fat tissue and from their muscles as fuel.

"Our results suggest that changing the timing of when you eat in relation to when you exercise can bring about profound and positive changes to your overall health,” said Dr. Javier Gonzalez. "We found that the men in the study who exercised before breakfast burned double the amount of fat than the group who exercised after.”

While there was no difference in total weight loss or conditioning level between the two exercise groups, the ones who exercised before eating decreased their risk for diabetes and heart disease to a greater degree because of better blood sugar control.

"The group who exercised before breakfast increased their ability to respond to insulin, which is all the more remarkable given that both exercise groups lost a similar amount of weight and both gained a similar amount of fitness,” Gonzalez said. “The only difference was the timing of the food intake."

The muscles from those who exercised before breakfast had greater increases in the key proteins involved in transporting glucose than their counterparts. Researchers were surprised to discover even after six weeks of working out those who exercised after breakfast had no better insulin response to eating than those in the control group.

"This work suggests that performing exercise in the overnight-fasted state can increase the health benefits of exercise for individuals, without changing the intensity, duration or perception of their effort,” said study co-author Gareth Wallis. “We now need to explore the longer-term effects of this type of exercise and whether women benefit in the same way as men."

Click here to read more in the Journal of Clinical Endocrinology and Metabolism.