48: Dietary Fiber: Tackling Constipation on GLP-1s

Jan 15, 2024

Like many medications, GLP-1 drugs come with side effects and one of the most common (and bothersome!) among them is constipation. Even if you're not taking anti-obesity medication, constipation remains a common problem for many, which is not only uncomfortable, but also detrimental to your well-being. 

In this episode, I’m looking at the pivotal role fiber plays, not only in combating this side effect, but also in your overall health and weight management. We’ll dive into the practical ways you can increase your fiber intake and explore some of the other benefits of a high-fiber diet, including its positive impact on the gut microbiome.

How Do You Know If You Have Constipation?

Constipation isn't just about not going to the bathroom for a day or two (in fact, only 80 percent of people will go have a bowel movement daily - about one in five might go two or three days in between). It’s actually not a problem if you go a few days in between bowel movements. 

Constipation is when you find that you are getting symptoms such as lower abdominal pain, cramping, or having to strain really hard when you’re on the toilet. This may also lead to  potential complications like hemorrhoids and fissures.

If this is a challenge for you, or you know that you might be starting on one of the anti obesity medications–especially ones in the GLP-1 family where gut motility is slowed down–it’s important to understand the steps you can take to combat constipation.

Strategies to Combat Constipation

When it comes to constipation, ensuring that you’re well hydrated and getting enough movement in is key. On top of that, your fiber intake is important, too.

For women, we want to aim for about 25 grams of fiber a day (30g is even better!) and doing a nutrition audit can help you reach these targets. This is by no means in the name of being restrictive or feeling like we're on Weight Watchers and counting points - it’s simply to get an assessment of where you're at.

Depending on what you can handle, try to do an audit for anywhere between three and seven days to see how much fiber you’re getting. Most of my patients that come in are getting around 15 grams of fiber. And inevitably, if they're at that amount, they're going to end up getting constipation as we either put them on a medication or increase their dose. 

So getting ahead of the problem is always better than waiting for you to have this crippling constipation and then not wanting to take the medication. But the key question is: How do I get this much fiber into my diet?

Increasing Fiber Intake

A lot of people tend to think of things like fiber gummies to increase their intake, but it’s not always the most effective option. I don't often see people getting amazing results with these and if you look at how they produce them, you really don't know how much fiber you’re getting in the gummy. 

Due to the mixing process, a lot of it might have fallen to the bottom of the gelatinous material that they use. And so there's not a guarantee–as with all supplements–how much fiber is actually in it (unless you really know the company and what they're doing behind the scenes). So essentially you end up having a glorified candy experience, which doesn’t really do much for your stool.

It can be much more effective to make sure that you are getting some type of fiber source with every meal or snack. For example, if you normally like to have eggs at breakfast, you might now stick some green beans on there or half an avocado. In the same way that we're looking with every meal or snack whether protein is involved, we also want to look at whether fiber is involved as well.

High Fiber Foods

When it comes to incorporating more high fiber foods into your diet, this is always an area where I’d recommend meeting with a skilled registered dietitian who can discuss ideas based on your preferences. But when I think about fruits, foods like apples and pears are really good sources of fiber. In terms of vegetables, broccoli is an excellent source. 

Legumes or beans are another great source of fiber. Sometimes people worry about the carbohydrate content in them and shy away from foods like chickpeas, for example. But remember, whenever we're combining fiber and protein with that carbohydrate, the glycemic load, meaning how much our blood sugar level goes up, is greatly reduced. 

Avocados have 10 grams of fiber and even if you don’t eat the whole avocado (as they are quite calorie dense), it is certainly going to move you closer to your goal. Hemp hearts, chia seeds, and different whole grain products are also high in fiber.

Something else to consider–although this doesn’t work for everyone–are products that are processed to get more fiber in there. One of my most recent obsessions is The Better Bagel,  which has 25 grams of protein and over 30 grams of fiber. 

But it’s also important to keep in mind that with fiber, it's a slow game. You don’t want to go from where you are now to all the way up overnight. If you do it in a way that doesn't make sense and jump 10 levels higher, you’ll end up thinking “that didn't work for me.” But it's really because you did it too quickly and jumped too far ahead.

However, if you are doing all these things and they're not working out for you, it’s always worth talking to your doctor. It's not always just about upping this fiber content for you to get the results that you want. Getting a second opinion on this might help you to understand what needs to be done to get better results.

Fiber and the Gut Microbiome

Beyond alleviating constipation, fiber plays a pivotal role in nurturing a healthy gut microbiome. Trillions of bacteria in your gut aren't just passive spectators—they actively process your food. A balanced diet rich in fiber acts as a prebiotic (food for the “good” gut bacteria), influencing the microbiome in ways that support overall well-being. And so a lot of what I work on with my patients is making sure that they are nutritionally supporting themselves in a way that we, at this moment, think is helpful.

If you want to learn about the role of fiber in a lot more detail and have the opportunity to ask me questions, take a look at my mini course: Optimizing Fat Loss and Maintaining Muscle While on a GLP-1

This course is perfect for you if you are going to start a GLP-1 or you're already on one and want to fine tune your approach. What's really unique about this course is that you can leave questions, which I will answer either in a monthly Q&A call or in a video response.