Poor Digestion Can Cause Bloating & Fatigue – Part 2: Carb & Fat Digestion

Maximize carb & fat digestion and absorption to reduce gut symptoms and increase energy

This is part 2 of a two-part series on how poor digestion of your macronutrients (carbohydrates, protein, and fat) can lead to fatigue. Part 1 outlined the importance of chewing, symptoms that you may not be chewing enough or digesting protein appropriately, and tips to improve digestion. This article highlights symptoms associated with maldigestion of carbohydrates and fats plus recommendations to support digestion of these important foods.   

As described in Part 1, your digestive tract is like an assembly line: one action triggers the next action and so forth to break apart the food you eat into the smallest possible pieces for absorption and utilization of the nutrients.   

Chewing is the First Step of Digestion

I wrote about chewing your food in Part 1 but it’s important enough to mention again. While you are chewing, saliva is secreted in your mouth. Saliva contains amylase which is an enzyme to digest carbohydrates and a small amount of lipase enzyme to digest fats. If you’re eating quickly and not adequately chewing your food, you are missing out on important enzyme activity.  Review the tips for adequate chewing in Part 1.  

Carbohydrate Digestion

Carbohydrates are found in grains, beans, legumes, vegetables, fruit, sugar, and other sweeteners. Carbohydrates are digested into single monosaccharides which are absorbed through your gut lining into your liver, packaged up as glucose, and sent into your blood stream to be used as energy.  This is the energy your body uses to move, think, and breathe.  Glucose powers your heart, muscles, lungs, brain, and more. Carbohydrate digestion is crucial for energy production.    

As mentioned above, carbohydrate digestion starts in the mouth with the amylase enzyme in saliva. Next, in the stomach, gastric amylase continues to break down the carbohydrate and the food eventually turns into liquid. Also in the stomach, as described in Part 1 of this series, hydrochloric acid (HCl) purposely increases acidity in the stomach. Once food in the stomach moves to the small intestine it is this acidity that triggers the pancreas to release pancreatic amylase for further carbohydrate digestion including breaking apart pieces of carbohydrates into disaccharides.

As the food moves through the small intestine, it interacts with another set of enzymes called brush border enzymes, which are made by the cells lining the small intestine at the site of absorption. Brush border enzymes break disaccharides into monosaccharides which is the final step before absorption through the small intestine lining. These enzymes are made by your intestinal cells so if there’s inflammation from Celiac, SIBO, Crohn’s, or leaky gut these enzymes may not be able to perform this important last step. Those with lactose intolerance lack the brush border enzyme lactase to digest milk products. 

Symptoms of Poor Carb Digestion

• Bloat and distention in the upper or lower abdomen which may get worse as the day progresses
• Gas, usually without odor, tends to be worse in the evening or can occur with bowel movements
• Diarrhea or constipation
• Burping
• Fatigue – glucose creates energy in your body so if you are not digesting your carbohydrates properly, you’re not getting enough of your best fuel source.

Carb Digestion Support Tips

• Just like with protein, chew your food 10-20 times per bite. This will necessitate slowing down while eating. Put your fork down between bites.
• Prepare carbohydrates for maximize digestion:
  • Eat mostly cooked vegetables rather than raw vegetables: cooking breaks down fiber taking pressure off your digestive tract to do all the work.
  • Soak whole grains and beans: soaking grains and beans in water and rinsing thoroughly before cooking makes these carbohydrates easier to digest.
  • Cook beans appropriately: see Jill’s tips on cooking beans; beans contain both protein and carbs so they can be difficult to digest.    
• Reduce consumption of raw hard-to-digest vegetables, including shaved Brussel sprout salads, cabbage salads, kale, cauliflower, and broccoli.  Eat these vegetables cooked instead. 
• Take digestive enzymes with a blend pancreatic (amylase, lipase, and protease) and disaccharide enzymes (maltase, sucrase, lactase, invertase, and glucoamylase).   

Fat Digestion

Dietary fats are found in nuts, seeds, fish, meat, olives, coconuts, all types of cooking oils, and fried foods. Fats are extremely important as they are used for energy and as building blocks for hormones, your brain, and your trillions of cell membranes. Fats also provide satiety and reduce blood sugar swings. 

A small amount of fat digestion starts in the mouth since saliva contains some lipase, the fat digesting enzyme. Gastric lipase is secreted in the stomach where fat digestion really kicks off. Along with protein and carb digestion, HCl also has a role in fat digestion since the acidity it creates in the stomach sends a signal to the pancreas to secrete pancreatic lipase and to the gall bladder to secrete bile.

Bile is made in the liver and concentrated and stored in the gallbladder. When you eat fat, such as olive oil, bile is secreted into the upper part of the small intestine called the duodenum. Bile is an emulsifier which breaks fats into smaller pieces. It acts like Dawn dish soap cleaning off ducks after an oil spill. Once the fat is dispersed into small pieces, pancreatic lipase acts like scissors to cut it up into even smaller pieces called free fatty acids. A final stage of digestion happens at the lining of the small intestine with brush border lipases allowing for absorption.  

You may have difficulty digesting fat if your gall bladder has been removed. Without the gallbladder, bile is not concentrated and is not secreted into the small intestine at the appropriate time.

Symptoms of Poor Fat Digestion

• Floating stools – undigested fats will remain in your stool and stools will float in the toilet water like a buoy
• Light colored stools – proper amounts of bile help maintain the appropriate brown color
• Nausea – poor fat digestion in the stomach often causes nausea
• Diarrhea – once bile does its job most of it reabsorbs back to the liver to be used again. If it doesn’t reabsorb diarrhea can occur. 
• Constipation – bile helps to lubricate stool so constipation can be result of insufficient bile.
• Fatigue – fats are the building block of energy-producing hormones estrogen, progesterone, testosterone, and cortisol. Fats are also used as an energy source through the metabolic process called beta oxidation. If you are not digesting fats well, you may feel tired.    

Fat Digestion Support Tips  

• Eat “cholagogue” foods, such as beets, arugula, artichoke, turmeric, radishes, and dandelion greens, which signal the gallbladder to secrete bile.
• Supplement with Lipase enzyme. This is included in a pancreatic enzyme blend or can be purchased on its own. If you experience nausea after eating fats, lipase often helps.   
• Supplement with Bile if you experience constipation. This is not recommended if you are experiencing diarrhea. 
• Eat more fiber if you experience diarrhea as fiber helps bind up excess bile in the colon. Ground flax seeds, psyllium husk fiber, whole grains, and beans are helpful. 
• Take probiotics to support microbiome balance in the colon which helps diarrhea caused by excess bile. 

Optimizing your digestion of carbs and fats will help you obtain valuable nutrients from these foods and feel improved energy with less gut symptoms. It will also help you widen your food choices as variety is key to a healthy diet. 

Want to learn more about your digestion?  Consider GI Map with StoolOMX testing. 

At Be Balanced Healing, we use the GI Map stool test to assess microbiome balance as well as digestive function of protein, carbs, and fats. The test includes measures of digestive pancreatic enzymes and bile acids to provide a useful picture of macronutrient digestion. Learn more here https://www.diagnosticsolutionslab.com/tests/gi-map and https://www.diagnosticsolutionslab.com/tests/stoolomx-bile-acids-short-chain-fatty-acids-test.

Disclaimer: Nutrition therapy is not intended as a diagnosis, treatment, prescription, or cure for any disease, or as a substitute for medical care. Jen Marshall, Stacy St Germain, and Jill Dopp are not licensed medical providers. Nutrition plans are not intended as a substitution for traditional medical care, nor should they be interpreted as medical advice, but instead is an adjunctive and supportive therapy.