With diabetes, you need to keep your blood sugar levels within target to avoid the deleterious effects associated with uncontrolled blood sugar levels, such as blindness, heart disease, stroke, kidney failure and amputation. The recommended blood sugar levels correspond to 70 to 130 mg/dL at the start of a meal and below 180 mg/dL 2 hours after the meal. Keeping your blood sugar levels under control, or as close as possible to the levels seen in people without diabetes, is the best way to live healthy with diabetes.
Low Blood Sugar Levels
When your blood sugar level drop below 70 mg/dL, it is considered hypoglycemia and you may experience symptoms such as fatigue, weakness, shakiness, sweating, hunger, dizziness, difficulty speaking, confusion and irritability. If you feel very tired after a meal, it may be because your blood sugar levels are too low. If you do not have enough energy, or sugar circulating in your bloodstream, you will feel tired. Hypoglycemia within a few hours after eating can be due to taking an excessive dose of insulin or diabetes medications, not eating enough carbohydrates at the meal, being too physically active or drinking alcohol.
High Blood Sugar Levels
High blood sugar levels, also called hyperglycemia, may be responsible for the fatigue you experience after a meal. If your meals contain too much carbohydrate and lead to blood sugar levels above 180 mg/dL one to two hours after eating, you may feel tired because although there is plenty of sugar circulating in your blood, this sugar is unable to enter your cells to supply them with energy. Other symptoms of hyperglycemia can also include excessive thirst, increased urination and blurry vision, but some people will only feel some fatigue.
Determining the Cause
If you have diabetes and feel tired after a meal, the best way to determine the cause of your fatigue is to check your blood sugar levels. It is best to check first before the meal to see where your blood sugar levels are to start with. Ideally, your blood sugar levels should be between 70 and 130 mg/dL. Then, check again 2 hours later. If your blood sugar levels are below 70 mg/dL at that time, hypoglycemia is your problem. If your blood sugar levels are above 180 mg/dL 2 hours after your meal, hyperglycemia is to blame. Repeat the experience a few times to ensure you have found the cause of your problem. If your blood sugar levels do not appear to be the source of your post-meal fatigue, talk to your doctor.
Getting Your Sugars Under Control
The key with diabetes is to eat foods that keep your blood sugar levels balanced. Spacing your meals evenly throughout the day and consuming the right amount of carbohydrates at each meal is important. If you have determined that hypoglycemia makes you feel tired after eating, identify the cause of your hypoglycemia and correct it. Remember that if your blood sugar levels drop below 70 mg/dL, you need to treat it by taking a few glucose tablets, 1/2 cup of fruit juice or 1/2 cup of regular soft drink. If the cause of your post-meal fatigue is hyperglycemia, you will need to look at your carbohydrate intake and reduce it until you find the right amount that helps you keep your blood sugar levels below 180 mg/dL 2 hours after the meal. Talk to your diabetes team for help managing your blood sugars.
