Blood sugar is greatly influenced by your diet and the amount of foods that your consume, as well as the types of foods you consume may affect your blood sugar levels. Food is comprised of protein, fat and carbohydrates, and each of these components are necessary elements of a healthy diet, Carbohydrates, however, typically have the most pronounced effect on blood sugar levels. Carbohydrates are found in foods such as potatoes, rice, bread, cereals and pasta. They are also found in milk, fruit, sweets and yogurt. In addition, carbohydrates can cause an excessive rise in blood sugar, especially after meals. People with diabetes need to keep track of their carbohydrate consumption and should spread out the consumption of carbohydrates throughout the day.