Reactive Hypoglycemia

Most people correlate hypoglycemia (low blood sugar) with diabetes.

Truth is, the phenomenon of hypoglycemia (also known as ‘sugar crash’) doesn’t happen exclusively with diabetes.

Reactive hypoglycemia or postprandial hypoglycemia usually happens within a few hours after eating a meal.

It is different than fasting-induced hypoglycemia, or a sugar crash that happens during prolonged fasting due to depleted cortisol.

Doctors and scientists don’t know exactly what causes reactive hypoglycemia in the first place.

The general expert opinion holds it’s related to the foods someone consumes and / or the time required to digest these foods and release their constituents (glucose, amino acids, fatty acids, etc) into the bloodstream.

If you are someone that experiences frequent blood sugar crashes or feel the negative symptoms of hypoglycemia (such as dizziness, tiredness, feeling shaky or trembling, hungry, etc) within a few hours after meals, it may be a good idea to seek the advice of your trusted doctor or nutritionist.

Most likely, you will need to implement some potential changes in your diet and / or lifestyle in order to help you control your blood sugars better.

Hypoglycemia Without Diabetes

Reactive hypoglycemia and fasting hypoglycemia are the only two types of non-diabetic hypoglycemia.

Well-established sources, such as the Hormone Health Network, state that having hypoglycemia without having diabetes is usually rare.

Accordingly, most individuals who experience reactive hypoglycemia are either diabetic or in the prediabetic stage.

In the real world though, it’s actually quite common to experience hypoglycemia without having diabetes.

In every case, hypoglycemia is correlated with low blood glucose levels.

You obtain glucose from almost any food you eat, not just from sugary or starchy foods.

Glucose can come from fruits, vegetables, nuts, seeds, grains, dairy and even some other animal products (i.e. liver). 

Glucose serves as fuel and is our body’s primary source of energy.

The human brain is also dependent on the presence of glucose as an energy source, which is why you can’t think right, feel tired, fatigued and irritable when you have hypoglycemia.

The proper regulation of glucose in the body, such as its transportation to the brain, muscles and other cells requires the action of a specific hormone, called insulin. 

Insulin is produced and secreted by the beta cells of the pancreas.

Disturbances in the production, secretion and action of insulin are one of the tell-tale signs of diabetes.

When your body can’t produce enough insulin to regulate your blood sugar or when your cells respond very poorly to the already-existing insulin in your blood (insulin resistance), you have type II diabetes.

Type II diabetes is different from Type I diabetes.

In Type I your pancreatic beta-cells that normally produce and secrete insulin don’t function at all.

Nevertheless, problems with insulin don’t occur only in diabetes.

Reactive hypoglycemia occurs in the first place because at some point your circulating insulin levels reach a way-above-normal range, causing your blood sugar to crash afterwards.

The effects of hypoglycemia are usually felt at glucose values of 70 mg / dL or lower.

According to the American Diabetes Association (ADA) these values are when you ‘enter’ the hypoglycemic zone.


Most individuals suffering from reactive hypoglycemia don’t typically have other underlying conditions or co-morbidities.

Some factors that may contribute to reactive hypoglycemia include:

  • Prediabetes: It refers to the metabolic state of a person before him / her developing full-blown diabetes. At the prediabetic stage, the body is either not making enough insulin or the cells are less sensitive to it, which creates blood sugar abnormalities, such as reactive hypoglycemia.
  • Enzymatic deficiencies: Although not very common, a deficiency in pancreatic or gastric (stomach) enzymes may prevent someone from breaking down and absorbing the foods he / she consumes. That can affect energy metabolism (i.e. fats and carbs) and negatively affect blood sugar homeostasis.
  • Recent stomach surgery: These types of procedures can create complications and problems in the patient’s ability to digest and process food properly. Due to the operation, gastric emptying may be abnormally fast and the contents of the stomach may reach the first part of the small intestine (duodenum) at a very rapid pace, contributing to post-meal sugar crashes.


The conclusion or diagnosis of reactive hypoglycemia is reached based on the patient’s reported symptoms.

Patients should keep a food diary and write down their symptoms and reactions after each meal, in order for the doctor to recognize patterns and identify, as accurately as possible, what causes the issue. 

Doctors may require from a patient to complete a blood test if severe or frequent hypoglycemic episodes are suspected.

The most common and usual test is a blood sugar reading.

During this test, the finger of the patient is pricked and a blood glucose monitor is used for the reading.

Blood glucose values below 70 mg / dL are considered hypoglycemia according to the American Diabetes Association.

Other examinations used to determine hypoglycemia include an oral glucose tolerance test (OGTT) and a mixed meal tolerance test (MMTT).

For an oral glucose tolerance test (OGTT), the patient will drink a glucose syrup, while for a mixed meal tolerance test (MMTT) the individual will ingest a mixed macronutrient (fat, protein and carbs) beverage.

Your physician will examine your blood sugar levels before and after the consumption of these beverages to determine any irregularities. 

If your doctor suspects prediabetes, diabetes or other health conditions that may affect your insulin metabolism, he / she may require you to complete additional tests.


While it’s not necessary to have all the symptoms below to suffer from reactive hypoglycemia, the most common ones include:

  • Weakness
  • Fatigue
  • Tiredness
  • Sleepiness
  • Lightheadedness
  • Anxiety
  • Depression
  • Confusion
  • Dizziness
  • Irritability
  • Hunger
  • Shaking
  • Sweating
  • Tremors

These symptoms usually go away after consuming about 15 g of carbs.


In most cases, fixing reactive hypoglycemia doesn’t require the use of pharmaceuticals or drugs.

Even if the patient has undergone gastric surgery or qualifies for other risk factors that predispose him / her to reactive hypoglycemia, diet interventions are the preferred way of dealing with this condition.

When you experience symptoms of reactive hypoglycemia, the short-term solution is to consume 15 grams of carbohydrates.

If your symptoms don’t dissipate within 15 minutes, consume another 15 grams of carbohydrates.

If dealing with blood sugar crashes on a regular basis, you may need to make some long-term diet modifications to address the issue.

The following tips can prove useful:

  • Eat smaller, frequent meals that contain protein: Snack throughout the day with foods that contain some protein (i.e. boiled eggs, cheese, nuts, seeds, etc), or eat something every two to three hours. Protein provides satiety and above a certain point raises your blood sugar, but not so abruptly as simple sugars do. Protein-filled snacks give greater blood sugar stability than snacks rich in simple sugars and / or starch.
  • Avoid processed foods: These include biscuits, crackers, candy, baked goods, white flour products, milk chocolate and other ‘comfort foods’.
  • Avoid high-sugar snacks, such as fruit, without combining them with fat: Fruits are delicious, hydrating, nutrient-dense and full of fiber. Unfortunately, some of them contain very high amounts of natural sugars (fructose and glucose), which can disrupt your blood sugar homeostasis. Consuming some fat with your fruit will also ensure better absorption of the fat-soluble vitamins found in them (A, D, E, K) and will delay gastric emptying (and thus, the absorption of sugars into the circulation).
  • Eat a balanced diet: No matter what diet you follow, it should provide you with all the macros (protein, fats, carbs) and micros (vitamins, minerals, trace elements) your body needs to thrive. Some people witness their blood sugars to be steadier with a high-carb diet rich in whole fruits and vegetables, nuts and seeds. Other people notice better results with a high-protein, high-fat approach rich in animals products – meat, fish, eggs, dairy, organ meats (offal), while others with a mixed approach rich in both plant and animal foods.
  • Limit your alcohol intake: Moderate amounts of alcohol can cause your blood sugar to rise. Excess alcohol, however, can decrease your blood sugar levels, causing hypoglycemia, and even make your values reach dangerously low levels. When you drink alcohol always eat something at the same time to prevent these issues.
  • Avoid caffeine: Caffeine causes blood sugar fluctuations in some people, especially those with reactive hypoglycemia. Use caffeine alternatives, such as decaffeinated coffee or herbal teas.
  • Try to quit smoking: Nicotine can cause blood sugar ups and downs, as it alters the body’s ability to process glucose. It may also increase an individual’s predisposition to develop Type II diabetes or exacerbate a pre-existing diabetic state. You should be able to slowly taper off smoking through the use of prescription nicotine products, vaping, or other alternative techniques. 

You will see many websites and blogs claiming that this or that diet is the ‘cure’ for reactive hypoglycemia, but the truth is that there is no ‘one-size-fits-all’ approach when it comes to addressing this condition.

Certain people respond differently than others due to metabolic, genetic and /or epigenetic variations.

Generally, you should begin by modifying your diet according to the principles mentioned above.

Also, try to keep a food diary with you in order to identify what foods or food combinations negatively affect your blood sugars.

When to See a Doctor

The proper diet can help you improve your insulin sensitivity and balance your blood sugar, preventing post-meal energy crashes.

In case, however, that you have undergone surgery or are suffering from peptic ulcers, you may need to consult your doctor for further guidance.

In such cases, extra treatments apart from diet modifications, are oftentimes needed.

You should also proactively seek the advice of a primary care physician or nutritionist if your blood sugar issues pertain despite making changes to your diet.

Your physician will conduct the necessary tests to exclude diabetes or other comorbidities.

When your blood sugar levels are not tightly regulated and go up and down, they can predispose you to many serious health conditions, including:

  • Nerve damage
  • Vascular degeneration
  • Eye damage
  • Dental problems
  • Heart disease
  • Foot problems
  • Brain attack (stroke)

Takeaway Points

After you have determined that reactive hypoglycemia is indeed the cause of your blood sugar crashes, diet alterations are most often enough to resolve this issue and prevent future incidents.

If you continue to experience blood sugar crashes despite changes to your diet, consult with your doctor or nutritionist.

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This content is for informational and educational purposes only. It is not intended to provide medical advice or to take the place of such advice or treatment from a personal physician. All readers/viewers of this content are advised to consult their doctors or qualified health professionals regarding specific health questions. Neither Metabolic Body nor the publisher of this content takes responsibility for possible health consequences of any person or persons reading or following the information in this educational content. All viewers of this content, especially those taking prescription or over-the-counter medications, should consult their physicians before beginning any nutrition, supplement or lifestyle program.