If you’re eating a high protein diet of mostly animal-based foods, you may get constipated. But it’s not the protein that’s causing this problem. More likely, it’s the absence of fiber in the foods you’re eating.

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High protein, low carbohydrate eating plans have become popular for weight loss. But for some people, constipation is a common result.

Protein by itself does not cause constipation. But animal sources of protein, such as chicken and fish, don’t contain fiber. For some people, the result of eating these foods to excess can be constipation and bloating.

Read on to learn about protein’s role in constipation and how you can alleviate this problem.

There are many high protein food sources. They include:

  • red meat
  • poultry
  • fish and seafood
  • eggs
  • legumes and beans, including lentils and tofu
  • nuts
  • dairy products like Greek yogurt and cottage cheese
  • dietary supplements like protein powder, nutrition bars, and shakes

Some high protein foods, like nuts and legumes, contain fiber. Dietary fiber is an undigestible type of carbohydrate that comes from plants. Fiber may be soluble or insoluble, and both types support gut health. Insoluble fiber in particular helps you avoid constipation.

High protein foods like meat, poultry, and fish don’t contain any fiber. If you eat a high protein diet comprising solely or primarily of these foods, constipation may result.

Water and fluid intake is also necessary for avoiding constipation. Animal protein sources do contain naturally occurring moisture. However, their water content may not be enough to reduce constipation.

Dietary supplements like protein powder are usually made from plant sources like hemp or soybeans. They may also be made from dairy products, like whey (the watery portion of milk).

Some protein powders contain fiber, but many do not. Protein powders may also be high in calories and sugar. To know what you’re getting in any dietary supplement, including protein powder, always check the label.

What is constipation?

Everybody “goes” differently. What’s typical for you may not be for someone else. But, in general, constipation is defined as having fewer than three bowel movements per week.

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Protein causes constipation if your diet doesn’t include enough fiber and fluid. If you eat too much animal-based protein, you may be eating fewer high fiber foods.

It’s fine to eat lots of protein. It may only become problematic if you replace fiber-rich foods, like vegetables and beans, with animal-based protein.

There’s no doubt that protein provides important health benefits. Protein contains amino acids, which are needed to build and repair muscle tissue and bones. Protein is also necessary for hormonal health. Eating protein makes you feel full and regulates blood sugar, which can be helpful when you’re trying to lose weight.

Eating too much animal protein has a downside if you don’t balance a high protein intake with other foods. This can be detrimental to bowel health and can cause symptoms like constipation, gas, and diarrhea.

Emptying your bowels regularly (“pooping“) is necessary for maintaining overall health and for optimal digestive tract function. Having bowel movements daily, or at least three times per week (every other day), is how your body rids itself of toxins and waste products.

If you’re constipated, you run the risk of serious complications, like bowel perforation or fecal impaction.

If your bowel movements have become irregular and you suspect that a high protein diet is to blame, adding fiber and fluid to your diet should help.

Constipation can make you feel sluggish. But increasing your physical activity level can help your bowels move more freely.

The occasional use of a constipation-reducing over-the-counter medication may be beneficial. These include bulk-forming laxatives and stool softeners. Get your healthcare professional’s approval first, especially if you’re pregnant or have an underlying condition like diabetes or kidney disease.

Try these strategies for reducing constipation and maintaining bowel health while following a high protein eating plan:

  • Balance each meal, so you’re including a high fiber food along with protein. This can be as simple as adding a side salad or vegetable to your dinner plate, along with a lean piece of chicken or fish.
  • Substitute plant-based, protein-rich foods like beans and tofu for animal proteins like meat or turkey.
  • If your daily go-to breakfast is eggs and bacon, try alternating between eggs, oatmeal, and Greek yogurt instead. You can further increase the fiber content of these healthy foods with add-ins like chia seeds or flax seeds.
  • Choose high fiber snacks between meals, such as a handful of almonds or a fruit. Prunes may also be a good choice.
  • Increase your fluid intake during and after meals. Fluids help move stool through your digestive tract and can reduce constipation. Water is usually best. If you’re trying to lose weight, avoid sugary fruit juices.
  • Increasing your physical activity level by exercising often can stimulate bowel function. Try taking a walk or bike ride after meals.

The amount of protein you need every day is influenced by several factors. They include:

  • the sex you were assigned at birth
  • pregnancy or lactation status
  • age
  • weight
  • activity level

Current guidelines for the recommended dietary allowance (RDA) for protein is 0.36 grams per pound of body weight. The RDA represents the minimum amount of protein you should eat daily. This may not be enough for very active people or for people who are nursing (nursing or chestfeeding).

You can use this U.S. Dept. of Agriculture (USDA) calculator to get a more concise idea about your individualized need for daily protein.

If your constipation is accompanied by abdominal pain or by symptoms like fever, nausea, severe bloating, or vomiting, let your healthcare professional know.

You should also see your doctor for constipation that lasts longer than 5 days or that doesn’t resolve with over-the-counter treatment.

Do protein bars constipate you?

Protein bar ingredients vary by brand. If you’re substituting protein bars for meals, and the bars you choose don’t contain fiber, they may constipate you.

Do protein shakes constipate you?

Protein shakes, like bars, may or may not cause constipation, depending on their ingredients. Powdered shakes are mixed with water or juice and may be less likely to cause constipation than protein bars. Ready-made shakes also typically contain water or some other type of fluid.

How much is too much protein in a day?

Experts don’t always agree on the amount of protein people should consume on a daily basis. The USDA recommends an individual aim for eating around 5.5 ounces of protein per day for a 2,000-calorie diet.

Eating a high protein diet comprised primarily of animal-based proteins can cause constipation.

You can reduce the constipating effects of this type of eating plan by increasing the amount of fiber and water you eat and drink daily. Exercising and eating more plant-based proteins can also help.