If you have diabetes, controlling your blood sugar through a combination of diet, exercise and medication can prevent serious health complications. Chronic high blood sugar, known as hyperglycemia, can damage your blood vessels and cause heart and kidney disease, blindness and nerve damage. You'll need to monitor your glucose levels closely, not only at home but with a periodic A1C test which measures long-term glucose control over the months.
Carbohydrates and Glucose
Of the three macronutrients -- fat, protein and carbohydrates, carbs are most easily converted in glucose by your body. The faster your food can be digested, the faster your glucose levels rise. Sugar and starches, also known as simple carbohydrates, digest quickly and have the greatest impact on your blood sugar. Fiber, another type of carbohydrate, can't be digested by your body and slows digestion. You don't want to eliminate carbohydrates from your diet to control glucose, but you want to choose high-fiber carbohydrates that can add bulk to your diet without calories and help stabilize glucose levels.
Dangers of High Blood Sugar
Chronic high blood sugar weakens smaller blood vessels, which may cause them to rupture. When smaller blood vessels, also known as capillaries, burst, they no longer supply tissues, organs and nerves with oxygen and nutrients -- that's what causes the damage. Organs that rely on these smaller blood vessels, such as your heart and kidneys, are affected first.
Ketoacidosis is a serious condition that can lead to a potentially fatal coma if not treated. When high levels of glucose are in your bloodstream instead of in your cells being used for energy, your body begins to burn fat for fuel. Ketones, a byproduct of converting fat to energy can build up in your bloodstream, along with glucose. If your glucose levels are above 240 mg/dL, check your urine for ketones. If present, seek medical attention.
Eating to Prevent High Blood Sugar
You don't have to follow a low-carb diet to control glucose, but you do need to choose high-fiber, nutrient dense carbs that won't cause a sudden rise in glucose. It's important to eat at regular intervals to stabilize glucose -- every three to five hours. If you wait too long between meals, your blood sugar may drop; low blood sugar often leads to hunger, headaches and overeating, especially overeating simple carbs as your body calls for quick energy. Avoid foods with added sugars and choose vegetables, fruits, legumes and whole grains. Space your carbs evenly throughout the day. Every meal or snack should contain some combination of complex carb, protein and/or fat.
The Glycemic Index
Use the glycemic index as a guideline for choosing carbs that have little impact on glucose levels. The GI ranks carbs on a scale of 1 to 100 based on their potential to raise blood sugar. The lower a food scores on the GI, the less it affects your blood sugar. The GI isn't perfect -- some high-fat foods score low because fat slows digestion. You'll still need to use portion control and not overeat. Eating too many healthy foods can still lead to high glucose levels.
References
- National Institute of Diabetes and Digestive and Kidney Diseases; Prevent Diabetes Problems -- Keep Your Heart and Blood Vessels Healthy; April 2009
- Joslin Diabetes Center: How Does Fiber Affect Blood Glucose Levels?
- American Diabetes Association: Hyperglycemia
- American Diabetes Association: Ketoacidosis
