Constipated on a GLP-1? This is the best thing you could add add to your diet

The side effects of GLP-1s aren't much of a secret  — they can do a number on your GI tract and cause all kinds of digestion issues. And that’s why you might have noticed a new topic popping up in everything from your group chat to your newsfeed: Ozempic constipation (or Wegovy constipation, or Zepbound constipation, or name-your-GLP-1 constipation). But constipation isn’t just something uncomfortable to put up with, it can also point to a possible nutrition problem. That’s because it can be a sign you’re not getting enough fiber and fluids (something that can happen because you tend to eat less when you’re on a GLP-1). 

But while fiber is the MVP for healthy bowel movements, upping your intake too fast can have some pretty uncomfortable side effects. Here’s how to do things right.

Key takeaways

• GLP-1s reduce food intake, which can result in you eating less fiber — something that can cause constipation.

• If you up your fiber intake too quickly, it can cause bloating and cramping.

• Start slow, with an additional 5 to 10 grams over the course of a week, and pair it with fluids and exercise to help alleviate constipation.

First, it helps to know what exactly GLP-1s are doing in the body. They work by slowing stomach emptying, which keeps you feeling full for a longer amount of time. At the same time, they target receptors in your brain to reduce your appetite. So overall, “you have decreased food intake, and the medication leads to satiety,” says Dr. Juliana Simonetti, M.D., a board-certified internist at University of Utah Health and co-director of its Comprehensive Weight Management Program.

That means that you’re going to end up eating fewer calories and, as a result, might take in fewer key nutrients as well. This includes fiber — which is a big deal considering most Americans aren’t getting enough fiber as it is, taking a GLP-1 or not. Depending on your age and sex, you should be eating anywhere from 19 to 38 grams of fiber a day. But the most recent data shows that people in the U.S. get an average of 16 grams of fiber a day.

Fiber is essential for a few reasons: It helps you feel full, but it’s also in charge of keeping your stool soft and pliable, which allows it to more easily slide through your GI tract. Without it, food can slow down in your digestive system, ultimately leading to constipation.

Constipation is among the most common GLP-1 side effects, with one review finding that 8% of GLP-1 patients experience it. (In terms of frequency, it's just behind nausea, diarrhea, vomiting, and an upset stomach.)

Eating more fiber is one of the best things you can do for alleviating constipation, since it helps food move through your digestive system easily. However, “if you go from not eating much fiber to eating a lot of fiber, then it can also create problems,” says Simonetti. That’s because your body just isn’t used to the extra roughage. So adding fiber too quickly can lead to bloating, gas, and even cramping, says Ashleigh Hansen, R.D., a registered dietitian with Weight Watchers. Take these steps instead.

Ramp up slowly

If you want to add fiber without bloating, Hansen recommends you start by adding 5 to 10 grams to your current fiber intake over the course of a week. That comes out to one to two grams extra a day. So if you normally eat 14 grams of fiber a day, go for 15 to 16 grams. 

Once you stick with your new intake for a week, up it again by the same amount until you hit your goal. “An example would be to add one fruit each day for an afternoon snack,” Hansen says. “Then, the following week, keep the fruit as a snack, and add beans to your dinner.”

If you start to feel a little GI discomfort with the extra 5 to 10 grams of fiber a week, you can scale it back to adding an additional 3 to 5 grams each week. 

Have the right goal in mind

In general, most people need roughly 19 to 38 grams of fiber per day (women need up to 25 grams, while men need up to 38 grams, depending on their age). Being on a GLP-1 doesn’t really change that; it can just make it harder to reach that threshold thanks to your lower appetite. Because of that, “you may need to supplement fiber in addition to your daily food intake,” says Dr. Holly Lofton, M.D., a board-certified obesity medicine specialist at NYU Langone Health. If you’re not sure what to aim for or need more assistance getting there, talk with a registered dietitian, like those at Weight Watchers. (They are available to everyone, whether you’re a member or not!)

Get soluble and insoluble fiber

You’re going to also want to make sure you get both kinds of fiber through your diet: soluble and insoluble. “Soluble fiber dissolves in water and forms a gel-like substance,” says Hansen. That gel then traps fluids in the digestive system and helps keep stools soft, so they can pass through your intestines more easily. You can find soluble fiber in oats, beans, lentils, chia seeds, and parts of fruit.

Insoluble fiber, on the other hand, doesn’t dissolve in water and instead helps add bulk to stool. It also supports regular bowel movements. It’s found in foods like whole grains, nuts, seeds, and vegetables like carrots. 

Pair fiber with fluids

Don’t skip your hydration. If you up your fiber without also increasing how much water you drink, it can actually make the constipation worse, says Simonetti. That’s because fiber (particularly soluble fiber) uses fluid in the gut to form the gel that helps you feel full. But if you don’t have enough fluid in your system, “you have drier bowel movements and hard stools — making it even more difficult to go to the bathroom,” Simonetti explains.

Even if you’re not eating as much on a GLP-1, you can still get plenty of fiber in, especially if you prioritize veggies, fruits, and whole grains. Look for foods that give you the most bang for your buck. Split peas, lentils, black beans, and white beans all have 7 to 8 grams of fiber in a half-cup serving. “I like adding them into salads, roasting them with my vegetables, or making a dense bean salad,” Hansen says. Chia seeds are also hard to beat, with roughly 2 tablespoons offering 10 grams of fiber.

Look for high-fiber recipes to make the most of your meals when you’re on a GLP-1. Simonetti, for her part, recommends adding berries to your yogurt in the morning, or ground flaxseeds or chia seeds to oatmeal. 

If you’re really struggling to get fiber on your plate, consider a fiber supplement. “Metamucil can be a really helpful way of adding more fiber,” says Simonetti.

While fiber is an essential starting point for relieving constipation on a GLP-1, other lifestyle habits can also help you keep things moving. Here’s what to incorporate.

Stay hydrated

The more hydrated you are, the smoother things are going to go for you in the bathroom. When food moves through your gut, both nutrients and fluids alike get pulled out to be used by the body. And if you’re not working with enough hydration to begin with, you don’t have a whole lot of fluid remaining in your gut, leading to dry or hard bowel movements, says Simonetti.

If you’re used to drinking water only when you eat, you might not even realize you aren’t drinking as much water as you used to before going on a GLP-1. Try to sip on water throughout the day to ensure you’re getting enough without feeling overly full, and take a look at your urine to check if you’re getting dehydrated (ideally, it should be a light yellow color).

Be active daily

Moving your body can often get things moving in your gut — and this is true for people on a GLP-1 as well. Experts recommend that patients taking a GLP-1 who experience constipation pair adequate fiber and fluid intake with physical activity to help keep bowel movements regular. Hansen recommends doing something active after meals like taking a short walk, since physical activity helps get food moving through your intestines.

If adjusting your diet doesn’t bring you any relief, you may want to consider an over-the-counter option, like a laxative. Simonetti points to MiraLAX as a good option. “It’s an osmotic laxative, which pulls fluid into the bowels so the bowel movements won’t be so hard,” she says.

But if those measures don’t help with your constipation — or you start having abdominal pain or distension (meaning physical swelling, not just bloating) or can’t keep food down — loop in your clinician. Those could be signs of an obstruction. “There's always a concern, when you haven't gone to the bathroom for a few days, that it can lead to bowel blockage,” Simonetti says. “It's rare, but it can certainly happen.”

It’s not exactly surprising that when you’re eating less on a GLP-1, fiber — which already often gets left behind in the Western diet — tends to take even more of a backseat. But that can double your trouble. GLP-1s can cause constipation on their own, so ignoring fiber while taking a GLP-1 can make things even worse. 

The Weight Watchers GLP-1 Success Program can help you stay on track with your goals to help minimize the chances of constipation. The app helps you monitor how much fiber, hydration, and exercise you’re getting, and gives you plenty of inspo to reach your targets through 12k+ nutrient-dense recipes, on-demand workouts, and virtual Workshops you can pop into for support, pretty much whenever. In fact, 85% of GLP-1 Success members say that the program’s nutritional guidance helps them stay on track while on a GLP-1.*

Constipation is a relatively common side effect of taking GLP-1s, and the issue can be made worse if you aren’t getting enough fiber (something that can easily happen since you aren’t eating as much food in general). Slowly increasing how much fiber you take in, staying hydrated, and being physically active can make a big difference in your bowel movements. If that doesn’t help, you can always turn to over-the-counter options like fiber supplements, stool softeners, and laxatives. And if your constipation doesn’t improve, make sure to bring it up with your doctor.