Having type II diabetes, I found out that fat and protein can be worse than carbohydrates. The carbohydrate will cause a blood sugar rise in about 2 hours and can be controlled by portion controls. Fat, on the other hand, can cause a much sharper blood sugar rise about 6 hours later, and proteins will also affect blood sugar levels about 4 to 5 hours after eating. Your body burns sugar in order to provide the energy it needs for life and will break down any food source to provide the sugars it needs. Processed food will probably provide the quickest blood sugar increase, while complex carbohydrates like oatmeal take longer to convert to sugar and have a high fiber content that will slow down the absorption of the sugars form you intestinal tract.