What is reactive hypoglycemia?

Reactive hypoglycemia refers to a medical condition where a person experiences extremely low blood sugar after taking a meal that is rich in carbohydrates. Eating high carbohydrate foods may make your blood glucose levels to rise. However, people who experience episodes of reactive hypoglycemia produce more insulins than is required by your body. Insulin is a natural hormone produced by the pancreas, which helps glucose get into the blood cells. Excess insulin produced during reactive hypoglycemia may lead to a fall in blood sugar levels beyond the normal range. This condition is also known as postprandial hypoglycemia and usually happens within 4 hours of taking a meal.

Reactive hypoglycemia is different from hypoglycemia or low blood sugar that happens during fasting. The causes of the rare postprandial hypoglycemia and the common hypoglycemia are different, although you may experience similar symptoms in both forms of hypoglycemia. Postprandial hypoglycemia can occur in people with diabetes and those without diabetes. This medical condition is believed to be more common in patients who underwent gastric bypass surgery and people who are overweight.

Symptoms and causes

It is not yet known what is the actual cause of postprandial hypoglycemia symptoms. However, the symptoms may relate to the type of food that was eaten or changes in timing of food passing through the stomach and intestines. It is believed that hereditary fructose intolerance or stomach surgery could lead to postprandial hypoglycemia. Research shows that reactive hypoglycemia could be occur as a result of excess production of insulin by the pancreas after eating high carbohydrate foods. The pancreas will continue to produce insulin even after glucose is absorbed from the food that is digested. This will lead to abnormally low levels of blood glucose. However, it is not yet determined what really causes the increase in insulin production by the pancreas. One theory explains that a non cancerous tumor in the pancreas known as benign, could be responsible for the excess production of insulin. There are also explanations that show postprandial hypoglycemia could be caused by a deficiency in glucagon secretion. Sensitivity to the hormone epinephrine, that is released during periods of stress could also lead to postprandial hypoglycemia.

You may experience symptoms that are similar to reactive hypoglycemia even if you don’t have low blood glucose. Therefore, it is important you undergo a medical evaluation to determine whether your symptoms is as a result of postprandial hypoglycemia or other medical condition.

Symptoms of postprandial hypoglycemia include the following:

  • Fast heartbeat
  • Irritability
  • Sweating
  • Dizziness
  • Hunger
  • Shaking
  • Blurred vision
  • Faintness
  • Difficulty thinking

Reactive hypoglycemia treatment

Most people who have reactive hypoglycemia do not require treatment. The key goal for treating reactive hypoglycemia is to know which carbohydrates foods you need to consume in moderation or avoid so that you can prevent your blood sugar levels falling too low. In addition, you need to know which food you should include in your diet to help you keep your blood sugar levels stable. Because postprandial hypoglycemia is a chronic condition, you may need to adopt an appropriate diet plan throughout your lifetime. Your doctor may advise you to make the following changes to your diet:

  • Avoid taking sugary foods and drinks, especially on an empty stomach.
  • Eat a well balanced diet that includes fish, poultry, dairy products, nonmeat sources of protein, and foods that are rich in fiber such as whole grains, vegetables and fruits.
  • If you are taking alcohol, make sure you eat. Avoid sugary soft drinks as mixers.
  • Have a regular physical exercise. Exercising regularly will help increase uptake of glucose, hence reducing excessive insulin release by the pancreas.
  • Take small meals frequently throughout the day. Your meals should not be more than 3 hours apart.

In case you had stomach surgery such as gastric bypass you may require further evaluation by your doctor. However, your doctor may still recommend you adopt the above diet changes.


Reactive hypoglycemia symptoms can be managed by making changes to your diet. If you are experiencing episodes of postprandial hypoglycemia, you may adopt the following diet plan:

  • Morning plan

It is important you take a meal immediately after waking up in the morning. For a good breakfast, you can have complex carbohydrates instead of simple carbohydrates, including proteins. For example, you can take a couple slices of whole grain bread together with hard boiled eggs and cinnamon. In addition, you can take oatmeal, honey and unsweetened yogurt. Also, you can take foods that are high in soluble fiber, such as lentils, dried beans, vegetables and fruits that have their skin. Taking foods that have high soluble fiber can help slow down the process of carbohydrate absorption, which may help stabilize your blood sugar levels. Also, make sure you are mindful about the juice that you are consuming. It should not contain added sweeteners and you should limit it to 4 to 6 ounces during breakfast. Caffeine drinks can make your blood sugar levels to fall too low. You may opt for green tea or decaffeinated coffee instead. If you are not sure whether caffeine drinks may affect your blood sugar levels, you should discuss it with your doctor.

  • Mid morning plan

For your mid morning snack, you can choose to have fruits. Fruits are a good source of vitamins and minerals, and contain natural sugar that is used to fuel your body. You may choose to eat fruits together with proteins so that you can keep your blood sugar levels stable. You may take a banana together with seeds or nuts as your mid morning snack.

  • Lunch plan

For your lunch plans, you may choose to have chickpeas, tomatoes, chicken and vegetables. Also, you may choose to have baked sweet potatoes, grilled fish and salad as your lunch. Sweet potatoes are rich in antioxidants, which may help regulate your insulin amounts.

  • Mid afternoon plan

It is important you take complex carbohydrates as your mid afternoon snack. Complex carbs such as brown rice, legumes and whole wheat bread are slowly digested. That means glucose is slowly released which can help stabilize your blood sugar levels.

  • Dinner plan

For your dinner, you may take complex carbs and proteins. You can choose to take a glass of low fat milk.

  • Bedtime plan

It is important you take a snack during bedtime so that you can stabilize your blood sugar throughout the night. You can take unsweetened yoghurt together with walnuts as your bedtime snack.

Disclaimer: Please note that the contents of this community article are strictly for informational purposes and should not be considered as medical advice. This article, and other community articles, are not written or reviewed for medical validity by Canadian Insulin or its staff. All views and opinions expressed by the contributing authors are not endorsed by Canadian Insulin. Always consult a medical professional for medical advice, diagnosis, and treatment.