Understanding Carbohydrate Intolerance

Carbohydrates are a major part of most diets worldwide, providing energy for daily activities. Despite the common inclusion of all types of carbohydrates within dietary patterns, some people (an estimated 50 million Americans alone) experience discomfort or health issues after consuming certain carbohydrates. This condition, known as carbohydrate intolerance, can affect digestion and overall well-being. Understanding what carbohydrate intolerance is, its symptoms, causes, and how to adjust your diet can help manage or avoid unpleasant effects.

What Is Carbohydrate Intolerance?

In short, carbohydrate tolerance is a malabsorption problem. This type of intolerance occurs when the body struggles to digest or absorb certain types of carbohydrates properly. Unlike food allergies, which involve the immune system, intolerance usually results from enzyme deficiencies or problems in the digestive tract. When carbohydrates are not fully broken down, they can ferment in the gut, causing symptoms.

There are different types of carbohydrate intolerance, depending on which carbohydrate is involved. Some common examples include:

• Lactose intolerance: Difficulty digesting lactose, the sugar found in milk and dairy products.

• Fructose intolerance: Problems absorbing fructose, a sugar present in fruits, honey, and some vegetables.

• Sucrose intolerance: Difficulty breaking down sucrose (table sugar).

• FODMAP intolerance: Sensitivity to a group of fermentable carbohydrates found in various foods.

  
  

Each type affects the body differently but shares similar digestive symptoms.

Symptoms of Carbohydrate Intolerance

Symptoms usually appear within a few hours after eating carbohydrate-rich foods that the body cannot process well. Common signs include:

• Bloating and gas: Undigested carbs ferment in the intestines, producing gas.

• Abdominal pain or cramps: Gas and bloating can cause discomfort.

• Diarrhea or loose stools: Poor absorption leads to water retention in the intestines.

• Nausea: Some people feel sick after eating certain carbs.

• Fatigue or headache: These can occur as secondary effects of digestive distress.

Symptoms vary in intensity depending on the amount and type of carbohydrate consumed and individual tolerance levels. Some people may tolerate small amounts without issues, while others react strongly even to trace amounts.

Causes of Carbohydrate Intolerance

Several factors can cause or contribute to carbohydrate intolerance:

Enzyme Deficiencies

The body relies on enzymes to break down carbohydrates into absorbable sugars. For example:

• Lactase breaks down lactose.

• Sucrase breaks down sucrose.

• Fructase helps absorb fructose.

  
  

If the body produces insufficient amounts of these enzymes, carbohydrates remain undigested.

Gut Health and Microbiome

An imbalance in gut bacteria or damage to the intestinal lining can impair carbohydrate digestion. Conditions like irritable bowel syndrome (IBS) or small intestinal bacterial overgrowth (SIBO) may worsen intolerance symptoms.

Genetic Factors

Some people inherit enzyme deficiencies or sensitivities. For example, lactose intolerance is more common in certain ethnic groups due to genetic variations affecting lactase production.

Other Medical Conditions

Certain illnesses, such as celiac disease or inflammatory bowel disease, can damage the gut lining and reduce carbohydrate absorption.

How to Adjust Your Diet to Avoid Symptoms

Managing carbohydrate intolerance often involves dietary changes to reduce or eliminate problematic carbohydrates. Here are practical steps:

Identify Trigger Foods

Keep a food diary to track what you eat and when symptoms occur. This helps pinpoint which carbohydrates cause issues. Common triggers include:

• Milk and dairy products (lactose)

• Fruits like apples, pears, and watermelon (fructose)

• Wheat, onions, garlic (FODMAPs)

• Sweets and processed foods (sucrose)

  
  

Choose Low-Intolerance Alternatives

Once triggers are identified, replace them with suitable options:

• Use lactose-free milk or plant-based alternatives like almond or oat milk.

• Opt for fruits lower in fructose, such as berries, bananas, and citrus.

• Avoid high-FODMAP vegetables and choose tolerated ones like carrots, spinach, and zucchini.

• Limit added sugars and processed snacks.

  
  

Control Portion Sizes

Some people tolerate small amounts of certain carbohydrates. Eating smaller portions can reduce symptoms while maintaining dietary variety.

Incorporate Enzyme Supplements

Over-the-counter enzyme supplements may help digest specific carbohydrates. For example, lactase pills can improve lactose digestion. Consult a healthcare provider before use.

Focus on Balanced Nutrition

Ensure your diet remains balanced by including:

• Protein sources like lean meats, fish, eggs, and legumes.

• Healthy fats from nuts, seeds, and oils.

• Fiber from tolerated vegetables and whole grains.

  
  

Plan Meals Mindfully

Prepare meals that combine tolerated carbohydrates with proteins and fats to slow digestion and reduce symptoms.

Practical Examples of Dietary Adjustments

• Swap regular yogurt with lactose-free or coconut yogurt.

• Replace apple slices with strawberries or oranges as a snack.

• Use gluten-free pasta or rice instead of wheat-based pasta if sensitive to FODMAPs.

• Avoid sugary sodas and candies, choosing natural sweeteners like stevia or small amounts of honey if tolerated.

  
  

When to See a Doctor

If symptoms persist despite dietary changes, or if you experience severe pain, weight loss, or blood in stools, consult a healthcare professional. They may recommend tests to diagnose specific intolerances or rule out other conditions.

Where to Go From Here?

I am available to coach clients through the implementation of specialty and functional therapeutic diets related to carbohydrate intolerance. If you need someone to help you work through these issues, please reach out.

Remember to always prioritize your health!

References:

Fernández-Bañares F. Carbohydrate Maldigestion and Intolerance. Nutrients. 2022 May 4;14(9):1923. doi: 10.3390/nu14091923. PMID: 35565890; PMCID: PMC9099680

Burke M. Carbohydrate Intolerance and Disaccharidase Measurement - a Mini-Review. Clin Biochem Rev. 2019 Nov;40(4):167-174. doi: 10.33176/AACB-19-00025. PMID: 31857738; PMCID: PMC6892707