A good breakfast can help control your blood sugar all day!

From Science Daily:

"It is known that a carbohydrate-rich breakfast with low GI [glycemic index] can moderate increases in blood sugar after lunch. But my results show that low GI in combination with the right amount of so-called indigestible carbohydrates, that is, dietary fiber and resistant starch, can keep the blood-sugar level low for up to ten hours, which means until after dinner," says Anne Nilsson, a doctoral student at the Unit for Applied Nutrition and Food Chemistry and author of the dissertation.
Experiments also showed that the blood sugar increase following breakfast can be moderated in a similar way by eating the right grain products the night before.

Additionally, eating the 'right' grains can help decrease metabolic syndrome. This researcher also studied mental acuity and blood sugar levels after meals.

It turned out that subjects who had eaten low GI breakfasts could concentrate better and had a better working memory (a type of short-term memory) than the other group. These experiments also showed that healthy individuals with low glucose tolerance, that is with high rises in blood sugar than average following a meal, generally performed less well. "The findings indicate that people with great fluctuations in their levels of blood sugar run a greater risk of having a generally lower cognitive ability," says Anne Nilsson.

Apparently, the indigestible carbohydrates are the key to feeding the bacteria in the large intestine. This in turn ferments the carbohydrates into usable compenents like short chain fatty acids:

Anne Nilsson's studies show that components produced in the process of fermentation can enter the blood and favorably affect the regulation of blood sugar and the feeling of satiety, and they can help alleviate inflammatory conditions in the body, which in turn can entail a reduced risk of diabetes and cardiovascular diseases.