Sixteen adults between 18 and 30 years old were studied to investigate the effect of peanut butter consumption with a high glycemic index meal on blood sugar. Blood sugar levels were tested at 15, 30, 60, 90, and 120 minutes after eating a breakfast of white bread and apple juice. Two days later, participants ate the same breakfast with a serving of peanut butter (2 tablespoons) added to the meal.