Next, it’s important to be cognizant of foods that could cause a spike in blood sugar. These include simple carbohydrates (as opposed to the complex, fiber-laden types of carbohydrates you receive from whole grains, legumes, vegetables, etc.), sugary treats, and added sugars. (Generally, the more processed and refined a food is, the less it resembles the original plant source, and the faster and higher the blood glucose spike.)Â