Can a High-Protein Diet Make You Constipated? How to Balance Protein Intake and Digestion
Protein is a crucial nutrient for proper body function, necessary for muscle growth, proper development, and overall well-being.
Many athletes and TikTokers are taking praise for protein in stride, claiming a high-protein diet is the key to muscle development and weight loss. While protein, in the right doses, can certainly help with muscle mass and weight management, too much of it has potentially adverse side effects.
Because protein fills up the body, it can be tempting to limit the amount of carbohydrates, to counterbalance appetite. But, carbohydrates are important in their own right—without proper carb levels, individuals can lack fiber.2 As a result, stools don’t bulk up and going to the bathroom becomes an issue. It’s no wonder, then, that constipation has become a common complaint from people who are testing out high-protein diets.
Protein balance can be tricky while trying to maintain certain goals for your health. Experts weigh in on proper protein consumption, as well as ways to consume a high-protein diet without experiencing constipation.
How Much Protein Should You Eat Every Day?
The amount of daily protein each person needs varies and largely depends on your age, gender, overall health, and activity level.
In general, healthy adults need 0.8 grams of protein per kilogram of body weight each day.3 For example, someone who weighs 150 pounds should eat about 54 grams of protein a day. People who exercise frequently will need more protein—around 1.2 to 2 grams of protein per kilogram of body weight, research suggests.4
Dana Ellis Hunnes, PhD, MPH, RD, a clinical dietitian, assistant professor at UCLA Fielding school of public health, and author of Recipe for Survival, told Health that the recommended amount of protein for someone her size is 45 grams a day. Personally, she aims for about 54 grams of protein a day to account for the fact that, as a cyclist and swimmer, she’s extremely active. Any more protein than that would put unnecessary strain on her body.
“Extra protein above what we need—anything really over 1.3 grams per kg a day—just gets excreted, making your kidneys work harder,” Dr. Hunnes explained.
Can a High-Protein Diet Make You Constipated?
According to Dr. Hunnes, excess protein, which is very satiating, can cause you to eat less of other important foods that help keep your gut running smoothly. One of the first things people cut out is carbs.
Without enough carbs (and thus fiber) in your diet, you run the risk of becoming constipated.
“When high protein diets do not permit for enough fiber in the diet, for example with fruits and vegetables, this can lead to constipation,” said Neena Mohan, MD, an assistant professor of clinical medicine at the Lewis Katz School of Medicine at Temple University and a gastroenterologist at Temple University Hospital.
When you don’t consume enough fiber, food waste sits in the bowels, explained Dr. Hunnes. When that happens, the fecal matter becomes harder, more solid, and, ultimately, more difficult to expel.
Furthermore, research shows that high-protein diets are associated with a higher risk of inflammatory bowel diseases, potentially because the excess protein can alter the diversity and composition of the gut microbiota.5
By eating too much protein, “we are really doing our microbiome and GI tract a disservice,” Dr. Hunnes noted.
How to Eat More Protein and Avoid Constipation
All this to say, prioritizing protein in your diet does not automatically have to lead to constipation. There are a few things you can do to ensure regular bowel movements and maintain your protein intake.
The first step is to not overdo it. Simply eating more protein won’t make you stronger, leaner, or bulkier, explained Dr. Hunnes. Only regular, vigorous exercise combined with a well-rounded healthy diet can lead to those results. To Dr. Hunnes, the benefits of protein are often oversold and inappropriately marketed on food packaging labels. “Protein is not the panacea everyone wishes it to be,” she said.
Eating the right kind of protein is also hugely important. Dr. Mohan recommends variety within protein intake—you don’t need to just load up your plate with more grilled chicken. Switch it up with plant-based foods like black beans, lentils, and chickpeas. Seeds, nuts, and low-carb vegetables like leafy greens are great sources of protein and fiber, too.
Finally, it’s important to stay hydrated to prevent constipation. Both fluids and protein get filtered by the kidneys and “it helps to have sufficient amounts of fluid in the blood so the kidneys don’t have to work quite as hard,” Dr. Hunnes noted.
The more fluids you have in your body to dilute the protein levels in the blood, the easier it’ll be on the kidneys. Dr. Mohan recommends drinking six to eight glasses of water a day.
It’s always a good idea to consult with a doctor or dietitian if you’re thinking about making a major change to your diet. While upping your daily protein intake can be beneficial for some, doing so can also come with a number of risks and negative side effects, constipation being one of them.
Dr. Mohan suggests patients “discuss diet plans with your healthcare provider to follow a safe, nutritious and healthy diet.”