People with IPS often experience symptoms of low blood sugar even though their blood sugar levels are within a normal range. A doctor may recommend making changes to your diet to ease symptoms.

You frequently feel out of energy or shaky after a meal. You think you might have low blood sugar, or hypoglycemia. However, when you or a healthcare professional checks your blood sugar, it’s within the healthy range.

If this sounds familiar, you might have idiopathic postprandial syndrome (IPS). The term “idiopathic” means that the cause is unknown, and “postprandial” means that it occurs after a meal.

This article will discuss the causes and symptoms of IPS, as well as some recommended ways to help manage symptoms.

IPS is also referred to as pseudohypoglycemia or adrenergic postprandial syndrome.

People with IPS have the symptoms of low blood sugar, or hypoglycemia, up to 4 hours after a meal, but they don’t have low blood sugar levels. This sometimes occurs after eating a high carbohydrate meal.

IPS differs from hypoglycemia in a few ways:

  • Blood sugar levels in people with hypoglycemia are below 70 milligrams per deciliter (mg/dL). People who have IPS may have blood sugar levels in the normal range after eating, which is less than 140 mg/dL.
  • Low blood sugar levels can lead to long-term damage of the nervous system and kidneys, but these conditions don’t happen with IPS. IPS can disrupt your daily living, but it doesn’t lead to long-term damage.
  • IPS is more common than real hypoglycemia in people without diabetes. Most people who experience fatigue or shakiness after a meal have IPS rather than clinical hypoglycemia.

The symptoms of IPS are similar to low blood sugar levels, but they’re usually less severe.

The following IPS symptoms can occur after a meal:

  • shakiness
  • nervousness
  • anxiety
  • sweating
  • chills
  • clamminess
  • irritability
  • impatience
  • confusion, including delirium
  • a rapid heart rate
  • lightheadedness
  • dizziness
  • hunger
  • nausea
  • sleepiness
  • blurred or impaired vision
  • tingling or numbness in the lips or tongue
  • headaches
  • weakness
  • fatigue
  • anger
  • stubbornness
  • sadness
  • a lack of coordination

The symptoms of IPS don’t usually progress to seizures, coma, or brain damage, but these symptoms can occur with severe hypoglycemia. Additionally, people who have hypoglycemia may not have any notable symptoms in their daily lives.

Researchers don’t know what causes IPS.

However, the following might contribute to the condition, especially in people who don’t have diabetes:

  • a blood sugar level that’s in the lower levels of the healthy range
  • eating foods with a high glycemic index
  • a higher blood sugar level that rapidly drops but stays within the healthy range
  • an excess production of insulin from the pancreas
  • illnesses that affect the renal system, which includes the kidneys
  • a high consumption of alcohol
  • increased sensitivity to certain hormones, including noradrenaline and adrenaline

Most people who have IPS don’t need medical treatment. However, a healthcare professional may recommend that you modify your diet to stabilize blood sugar levels and balance levels of certain hormones, such as insulin.

The following dietary changes may help:

If these dietary changes don’t provide relief, a doctor might prescribe certain medications. Drugs known as alpha-glucosidase inhibitors, which are usually used to treat type 2 diabetes, might be particularly helpful for IPS.

However, the data on efficacy, or effectiveness, of this medication in treating IPS is very sparse.

If you experience symptoms of low blood sugar after eating, it’s best to talk with a doctor to determine the cause and the best course of treatment.

A doctor will ask questions about your symptoms and medical history. Additional testing may also be required, especially if you have severe symptoms or if an underlying condition may be contributing to your symptoms.

It might also be beneficial to keep track of the foods that you eat by completing a food diary, particularly if you experience anxiety after eating.

A doctor or dietitian can help identify any patterns that may contribute to your symptoms and provide suggestions for dietary modifications that may be beneficial.

What foods are good for idiopathic postprandial syndrome?

High fiber foods, heart-healthy fats, and lean proteins can help stabilize blood sugar levels and may be recommended for IPS. This includes foods like fruits, vegetables, whole grains, olive oil, avocados, poultry, tofu, and legumes.

Why do I feel shaky inside after eating?

Feeling shaky after eating may be a sign of idiopathic postprandial syndrome, along with other symptoms like chills, sweating, and lightheadedness. It might also be a symptom of postprandial reactive hypoglycemia, which occurs when you experience low blood sugar levels 2 to 5 hours after eating.

If you regularly experience any of these symptoms after eating, consider consulting with a doctor.

What conditions can mimic hypoglycemia?

Several other conditions can cause a similar set of symptoms as hypoglycemia, including anxiety, heat exhaustion, and migraine attacks. Measuring your blood sugar levels can help determine whether your symptoms are due to hypoglycemia or another condition.

If you frequently lack energy after eating but have healthy blood sugar levels, talk with a doctor about your symptoms and medical history. Working with a healthcare professional can help them identify a potential cause.

If you have IPS, making changes to your diet may help. This includes eating smaller meals and enjoying a variety of high fiber foods, lean proteins, and heart-healthy fats.