Yes, the popular diet can lead to some unfortunate GI symptoms.
This past year, the ketogenic diet made headlines as an extremely quick and effective way to lose weight.
The low-carb, high-fat eating plan, which consists of less than 5 percent carbs, 10-30 percent protein, and 65-90 percent fat, works by sending your body into ketosis — the metabolic state in which you burn fat instead of glucose for energy.
It’s helped many people shed stubborn fat, but for others, it’s been — quite literally — a pain in the butt.
Going keto, it appears, is giving tons of dieters frequent bouts of diarrhea.
According to health experts, your gastrointestinal (GI) system can take quite the hit when you switch up how you eat.
“Whenever you cut out certain food groups in your diet, an imbalance will occur,” Callie Exas, a licensed nutritionist and co-owner of The Wellthy Plate, told Healthline. “Our gut microbiome feeds off short chain fatty acids found in grains, fruits, and vegetables, which are limited on the keto diet.”
As a result, some people experience negative symptoms like nausea and fatigue — aka the “keto flu” — for a couple weeks as their gut microbiomes adjust to the meal plan.
Others, however, continue to suffer from tummy troubles throughout the diet.
Fat takes quite a bit of work to be broken down by the body and some people simply aren’t accustomed to metabolizing the amount of fat included in the keto diet.
Their bodies aren’t able to make use of all the fat they’re eating, so they try to expel of it. Hence, the runs.
“When you consume too much fat, the body can’t keep up with the breakdown and absorption. When unabsorbed fat gets into the small intestines and colon, more water will be pulled in to help its passage, resulting in watery diarrhea,” Exas explained.
For these unlucky folks, keto diarrhea is likely to be a permanent side effect of the diet.
Artificial sweeteners — such as sorbitol, maltitol, and xylitol — may also be to blame, some dietitians say.
Many people participating in the keto diet opt for these non-nutritive sugars in an attempt to limit carbs, but because sugar alcohols aren’t effectively absorbed in the gut, they often reach the large intestine undigested.
When this occurs, they tend to have an unpleasant laxative effect.
As if persistent diarrhea wasn’t bad enough, some participants also experience painful cramping, bloating, and constipation due to the lack of fiber in the keto diet.
“One of the single biggest challenges for many people on the ketogenic diet is constipation. Without adequate fiber, the GI tract can come to a screeching halt,” said Suzanne Dixon, a registered dietitian with The Mesothelioma Center in Portland, Oregon.
Fiber is crucial to gut motility and function, so when fiber is limited — as it is on the keto diet — digestive distress increases.
If you’re feeling backed up, you might assume a fiber supplement will balance things out, but many nutritionists advise against them.
“Many fiber supplements contain too many grams of carbohydrates. If you don’t carefully account for these extra carbohydrates in fiber supplements, it can prevent the person from reaching and maintaining full ketosis, which is the goal of the diet,” Dixon explained.
Rather, increase your fiber intake with nuts, seeds, leafy greens, and cruciferous veggies.
Be mindful of how much dairy you’re consuming. Dairy is known to cause GI upset, so try removing cream and cheese from your diet to see if that does the trick.
Additionally, while laxatives and anti-diarrheal medications may calm your bowels for a bit, they won’t ultimately resolve the issue at hand. They might even disrupt your gut microbiome and digestive system, causing further inflammation and GI issues.
Some dietitians recommend easing into the keto diet. Everyone has a different fat tolerance, so play around with different foods until you find something that works for you.
Lastly, stay hydrated. In general, people following the keto diet need to consume more water and electrolytes to avoid dehydration.
If you experience keto diarrhea, you run an even higher risk of becoming dehydrated. Not to mention, you lose less weight when you’re dehydrated, as your body has to work harder to burn off fat.
If you try making these adjustments and still run into tummy issues, it may be time to call it quits on the keto diet.
Chronic diarrhea can lead to heath complications, such as vitamin deficiencies, muscle deterioration, and electrolyte imbalance.
“If someone experiences keto diarrhea that doesn’t resolve with time as their body ‘adjusts’ to the diet, I would advise them to stop the diet. It’s simply not worth the risk to short- and long-term health,” Dixon advised.
In general, it’s smart to check in with your doctor whenever you change up your eating habits.
They can identify any underlying health issues, food intolerances, or allergies and help you figure out a meal plan that works best for you and your stomach.