Exercising before eating breakfast improves the body’s response to insulin and lowers the risk of type 2 diabetes and cardiovascular disease, according to findings from the universities of Bath and Birmingham.

In a six-week study, changes in meal timing and exercise allowed men who were overweight or obese to better control their blood sugar levels, reported study lead Rob Edinburgh, B.Sc.  

Edinburgh and colleagues compared results from two intervention groups who ate breakfast either before or after exercising, and a control group who made no lifestyle changes. The people who exercised before breakfast burned twice the fat as group members who did so afterward.

In addition, the muscles of the before-breakfast exercise group were relatively more responsive to insulin, wrote senior author Javier Gonzalez, Ph.D. This group’s muscles also showed greater increases in key proteins, specifically those that help transport glucose from the bloodstream to the muscles, he added.

“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,” said Gonzalez. “The only difference was the timing of the food intake.”

The study was published last week in The Journal of Clinical Endocrinology and Metabolism.