Breakfast, breaking the fast, eating breakfast increases energy levels it restores blood sugar after sleeping all night, and restore glycogen stores in the muscles and liver. Breakfast also reduces levels of the stress hormone cortisol. A literature from the University of Bath, found that skipping breakfast had no effect on metabolic rate and body weight control.
Specifically, it was report that both lean and obese adults expended less energy during the morning when remaining in the fasted state than when consuming a prescribed breakfast. Skipping breakfast has no long-term effects on weight loss, but may affect energy levels during the day. James A Betts et al Proceedings of the Nutrition Society, published online 13:1-11, 2016)