Dr Terry Graham

Typical breakfast foods such as toast and coffee affect your blood sugar and blood insulin levels when you least expect it – after lunch. That’s the word from University of Guelph nutritional sciences professor Terry Graham, who’s studying how food choices affect the body, and influence risk factors for disease such as diabetes and obesity.

“It is important that we learn what the nutritional challenges to the breakfast relationship would be in the standard Canadian person,” says Graham. “Once this is understood it will be possible to start giving consumers lists of healthy foods that would be good to consume, which in turn could lead to healthier eating choices.”

Graham, who chairs the Department of Human Health and Nutritional Sciences at Guelph, has spent his career working to understand how specific foods are used by the body, and how overall health is impacted. He says eating habits are changing rapidly, particularly for breakfast which, if it occurs at all, is often ‘on-the-run’ and includes fast foods.

In this recent study, he’s found that when caffeinated coffee is consumed with certain foods at breakfast it can have what he calls a ‘second meal phenomenon’. This means that the impact of the foods consumed at the morning meal on, for example, blood sugar and blood-insulin levels, are manifested after the second meal (lunch) is consumed. In the study, an average middle-aged male was given caffeinated or decaffeinated coffee paired with a cereal with a high glycemic index (a rank of carbohydrates in foods by their effect on blood sugar levels). Then Graham, along with graduate student Lesley Moisey, tracked blood sugar and blood insulin levels in the participants.

They found that in all participants no major effects were seen until a standard lunch was consumed three hours later. Then, through the second meal phenomenon, Graham saw that when participants had consumed caffeinated coffee with breakfast they had higher blood sugar and blood insulin levels for the following two hours than when they drank decaffeinated coffee.

From this, Graham concluded that caffeine is a crucial player in elevated blood sugar and blood insulin levels – which are both risk factors for diseases such as diabetes and obesity. He further suggested this is an important finding for people who are diagnosed or at risk for type 2 diabetes to avoid caffeine consumption as much as possible. In related research, supported by the Ontario Ministry of Agriculture, Food and Rural Affairs, Graham and graduate student Anita Mofidi Najjar are examining how the type of bread consumed at breakfast influences the second meal phenomenon. He’s also collaborating with scientists at Agriculture and Agri-Food Canada to understand the structure of commonly consumed breads and their affect on carbohydrate metabolism.

This research and findings are important aides to both the food industry in developing healthier products, and consumers in choosing better foods. He hopes future research will expand to include studies on foods enhanced with resistant starch and fibre influence risk factors for diabetes and obesity.

“The fact that diabetics are increasing in numbers is significant, but also concerning is that the people who are developing the disease are doing so at a younger age, which leaves greater chance for complications from the disease to develop,” Graham says.

Graham completed an undergraduate degree in physical education and graduate degree in physiology at Queen’s University in Kingston, Ont. He then completed post-doctoral work on the physiology of muscle carbohydrate metabolism in Copenhagen, Denmark.

He has been teaching at the University of Guelph since 1976. While at Guelph, he has maintained ties to Copenhagen by sending his graduate students to Denmark to complete studies as part of their research.

Graham’s research is supported by the Natural Sciences and Engineering Research Council and the Ontario Ministry of Agriculture, Food and Rural Affairs.

Written by Kaitlyn Little, SPARK University of Guelph’s student research writing program

For further information, please contact Dr Terry Graham using the Email contact form or by phone at 519 824-4120 ext 56168