Can You Lose Weight on a Gluten-Free Diet?


Gluten-free diets are all the rage right now. Most of us seem to know someone that is gluten-free. But what does that actually mean and why do people go on gluten-free diets? And what about people who say they’ve lost weight going gluten free?

First, let’s talk about what gluten is.

What is Gluten?

Gluten is one of the major proteins in wheat, rye and barley. When these grains are harvested, the seeds are stripped from the plant and processed into flour. Some types of flour are ‘whole grain,’ which means the bran and germ are not removed.

Other flour products are not whole grain. The main fiber components are removed. They are higher in starch and lower in fiber.

Regardless of whether the flour used to make a food product is whole grain or not, it will contain gluten.

Gluten plays a critical role in the baking process because it gives wheat flour baked goods their signature texture.

But why would something so seemingly harmless be such a problem for so many people?

Gluten-Related Disorders

According to the Celiac Disease Foundation, 1 in 7 Americans has a wheat- or gluten-related disorder. The most commonly diagnosed gluten-related medical condition is called Celiac disease. This is a medical condition where the affected individual experiences severe physical (and sometimes psychological) symptoms after consuming foods that contain gluten.

Until the last couple of decades, the reasons why Celiac disease develops were poorly understood. In the year 2000, researchers discovered the protein zonulin [1]. This protein sounds like something you would name an alien spaceport, but it is actually something we make in our intestinal tract.

Zonulin acts as a gatekeeper for the small gates between our intestinal cells. These gates are called tight junctions. In all humans, gluten triggers the release of zonulin, which causes these gates to open up a little [2].

In individuals with Celiac disease, when too much zonulin is released, the gates open up too wide and for too long.

When these gates open up and don’t close properly, any number of things can sneak into our blood stream from inside our intestines.

This might include undigested protein or peptides, viruses, bacteria or toxins we’ve ingested (think industrial chemicals, pesticides, by products of food manufacturing or any other chemical that should never be allowed to cross our intestinal lining ideally)[3].


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Under normal circumstances, these tight junctions should close up within 30 minutes of eating a meal.

However, in people with Celiac disease and some individuals who are not yet Celiac, but seem to have some type of gluten sensitivity or heightened reaction to gluten, these tight junctions can take hours to close back up again after consuming something with gluten [2].

Why is this a problem?

Immune Responses to Gluten

With these gates left open, and foreign proteins or other problematic things getting into our blood, our immune system goes crazy. Our immune cells are designed to recognize things that don’t belong in our blood and to neutralize them rapidly [4].

So, that’s good. But, in the case of this wide open gate, lots of things are getting in and lots of immune responses are happening, mostly in the gut and the tissues immediately surrounding the gut. This triggers a number of unpleasant side effects:

  • altered gut bacteria (dysbiosis) [5, 6]
  • diarrhea [7, 8]
  • constipation [6]
  • poorly digested food [10]
  • malabsorbed vitamins and/or minerals [11]
  • increased incidence of food sensitivities [12]

All of this, because this particular protein in some grains causes these intestinal junctions to open up. When this happens too often or very consistently, it is often referred to as ‘leaky gut,’ which is actually just a simplified name for intestinal hyper-permeability [13, 14].

Intestinal hyper-permeability can also be caused by other things, like altered gut bacteria, damage to the intestinal mucosa, long-term use of NSAIDs (non-steroidal anti-inflammatory drugs), heredity and damage to the intestinal cells themselves [15, 16, 17, 18,].

Now, before you get all hot and bothered and think this is another article about how gluten is bad for everyone, slow your roll.

If you’ll remember from above, I mentioned that this seems to be a problem mostly for people with Celiac disease and people with heightened immune responses or sensitivities to gluten. There is definitely a genetic connection for many people who react to gluten [19, 20].

And, in addition to genetics, there also needs to be some sort of trigger. Many people have genetic risks for Celiac or gluten disorders, but never have a problem.

So far, research seems to suggest that along with a genetic component, there also needs to be some sort of stress on the gut and the intestinal mucosa (major illness, prolonged psychological stress, shock, etc) in order for things to progress to the point that someone starts to have immune reactions.

Many people consume gluten-containing foods and have zero problems and that’s fine. It doesn’t mean they’ll never have problems or that they aren’t at risk for problems with gluten.

It just means that they don’t have the right mix of factors going on right now to trigger a disruption in this delicate intestinal gateway control mechanism.

Auto-Immunity and Gluten

To further complicate things, there’s this thing called autoimmunity. In some individuals, their immune system creates immune cells called antibodies. These antibodies, after being triggered by gluten (usually once it crosses the intestinal barrier and appears in their blood stream), turn around and attack their own cells and tissues [21, 22, 23].


Autoimmune diseases are a super hot topic in medical research right now because they are actually on the rise.


Well, the main connection between many autoimmune diseases (whether they are gluten-related or not), appears to be the gut. Intestinal hyper-permeability and the bacteria that live in our gut play a pretty giant role in the way our immune system reacts to things.


So, in people with Celiac disease and other gluten-related sensitivities, it is actually quite common to see other autoimmune disorders like Hashimoto’s thyroiditis, MS, dermatitis herpetiformis and gluten ataxia, for instance [18, 24, 25, 26].

Gluten is not necessarily the cause of these things, but it exacerbates the problems that allow these disorders to progress: gut stuff. Intestinal gates left open allow things to get in that cause immune reactions to happen [22].

On top of that, disturbances to the balance of bacteria in our gut (largely because we don’t eat enough of the right foods and too many of the foods that cause bad bacteria to over grow) begin to trigger even more immune reactions that start in the gut and trickle over into the body through….you guessed it: those gates that are left wide open.

Main points:

Gluten is a protein found in wheat, rye and barley. It causes intestinal cell junctions to open up and let things into your blood stream. People without any gluten sensitivity or Celiac disease usually do not experience harm from this but people who do react to gluten could experience a number of immune reactions.

This is a bunch of super complex stuff going on, and we haven’t even gotten to the weight loss thing, yet.

scale_upload-xSo, What About Weight Loss?

First, let’s differentiate between weight loss and fat loss. They’re not the same thing. Losing weight could mean losing fat, muscle or fluid, while fat loss really just means losing fat.

Most of us don’t have access to the super sensitive instruments that can be used to detect minute fluctuations in fat and fluid, so we use things like bio-electrical impedance (the scales you stand on that tell you your body fat), calipers or just standard scales.

None of these are really all that accurate, so if they are what you are using to determine if you’ve lost body fat, you could still be somewhere between 3-6% inaccurate, on average.

But, let’s get back to the question of weight loss. It is entirely possible that going on a gluten free diet can help you lose weight if you fall into the category of people who are Celiac or gluten-sensitive.

Intestinal inflammation, the kind caused by an immune reaction to a food, certainly can cause a good deal of fluid retention in and around the abdomen [16].

It is important to differentiate, though, that this is fluid you’re retaining, and not fat. This is fluid that you should NOT be retaining, so it is good if you lose it, but again, realize it is not the same as losing body fat. You will definitely feel better if it is gone, though.

Anytime you see fluctuations of more than about 1/2 a pound gained or lost overnight on your scale, there’s a good chance it is fluid you’re gaining or losing. Body fat changes happen at a much much slower rate (typically 0.5 – 1.5 lb per week, on average).

So what about body fat?

My answer to this is: Maybe.

You see, for my patients that go gluten free, I have a chat about not regularly relying on gluten free substitutions as a staple, if at all possible. These are things like GF brownies, GF cookies and GF chips.

These foods have a low nutritional value and tend to still be high in refined sugar and junk. They’re really not any ‘healthier’ than their gluten-containing counterparts.

If you cut out the packaged foods containing gluten and don’t replace them with gluten free counterparts, you’re likely to cut your calories pretty significantly, and this yields FAT LOSS.

This is obviously very indirect. People lose body fat on low carb diets for the same reason. They cut out the packaged food, reduce total calories because those foods are gone and the body adapts by burning stored fat to make up for the loss of caloric intake.

Can you occasionally eat gluten free pancakes on the weekend? Sure. Will it hurt you to indulge every once in a while with 100% corn chips at a restaurant with your friends? Not at all.

If the majority of the time you are consuming these higher calorie, lower nutritional density foods, gluten free or not, then you’re likely over consuming calories and then it is a problem.

Main points:


You can lose weight eating gluten free, but it will most likely be fluid you are retaining from inflammation caused by your digestive problems. If you do not have a gluten sensitivity, you may not be retaining any fluid anyway.


You can also lose body fat going gluten free, but really only if you cut out packaged foods, which is just reducing calories.


Let’s move on to applying this concept.

Take Action

How do you know if you should eat gluten free?


  1. Get tested. I test my patients for a broad spectrum of reactions to wheat and gluten. Not all individuals that react to gluten are Celiac. And some people are not yet Celiac, but are progressing toward it (based on repeated lab testing), therefore should still eliminate gluten.

Lab testing for a wide range of antibodies to gluten, non-gluten wheat proteins, and antibodies to zonulin and other intestinal junction proteins provides a great picture of just how reactive someone is or isn’t. If you don’t have to go gluten free, then your life will be easier.

2. Go gluten free. If you do not have access to a provider that will test you for more than just standard Celiac antibodies, go gluten free and see how you feel. Before you do, realize that you must be 100% gluten free in order to make a difference.


Immune antibodies that you might be making to gluten typically last in your blood for 3-8 weeks. Eating gluten once a week is still not gluten free. Most people notice a significant difference around week 3-4, if they are truly reacting to gluten.


Going gluten free is not as hard as it used to be, but it can still pose a problem for people who eat many of their meals away from home. If you don’t actually prepare your own food, you don’t know what goes into it for sure.

3. My best advice is to get very comfortable asking questions about preparation methods at restaurants and don’t ever accept this from a server: “I don’t know, but I’m pretty sure it doesn’t have wheat in it.” That usually means they actually have no idea and don’t want to go look.


4. Cook more at home and take your lunch or snacks whenever possible. Never assume something is gluten free just because it looks like it. Many foods are misleading (lunch meat, Twizzlers and many meat seasoning blends all have gluten).

If you don’t want to eat gluten, and don’t have testing to confirm a sensitivity to it, that’s ok too. There’s no unique nutritional value inherent to wheat, barley and rye that can’t be found in other grains or foods.

Plenty of people eliminate a whole food group without specific medical need. A couple good examples are vegetarians and people who eliminate foods based on religious beliefs.


Do what works for you.

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It is also definitely possible to heal ‘leaky gut,’ with the right mix of lifestyle interventions, a few supplements and some dietary adjustments. These things take time. You’re adjusting the entire ecosystem of bacteria in your gut, as well as trying to get your intestinal cells to heal and thrive.

All while leading a likely stressful life and balancing many responsibilities. Decide if it is the right time for you and if you can truly commit to this lifestyle change before you do.

Any questions? Comment below.


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  1. Rayna Clark March 11, 2016 at 1:30 pm · · Reply

    I appreciate that you have the science behind the gluten intolerance madness. It helps to better understand what’s happening in my body when the gluten comes to town (stupid cross-contamination).

    • SarahLewisRD March 11, 2016 at 3:41 pm · · Reply

      Thanks! I really don’t understand when I hear people say “Well, that’s just made up.” No, there’s actually about 16+ years of science looking at this…

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