Drinking that first cup on an empty stomach dramatically increases the insulin you produce when you do eat. The blood glucose response can be as much as 50 percent greater, say researchers from the University of Bath.
The metabolic damage is far greater than anything done by a bad night’s sleep, and regularly drinking coffee first thing could eventually lead to type 2 diabetes and heart disease, both caused by poor insulin control.
It’s a common habit. “We all know that nearly half of us will wake up in the morning and, before doing anything else, drink coffee, and the more tired we feel, the stronger the coffee,” said lead researcher James Betts.
But if we do need the coffee kick-start, make sure it’s done after breakfast. The researchers tested a group of 29 healthy men and women after they had experienced restful and disturbed nights’ sleep and were given coffee on an empty stomach and after eating breakfast.
(Source: British Journal of Nutrition, 2020; 1; doi: 10.1017/S000071145200001865)