Celiac Disease vs. Non-Celiac Gluten Sensitivity: What Personal Trainers Need to Know

celiac disease

Celiac Disease and gluten sensitivity are terms that are becoming more familiar and often thrown around, but all certified personal trainers should understand the differences.

Undoubtedly you, perhaps a personal training client, or someone you know avoids gluten. In recent years, gluten has taken on the mantle of “thing” that will kill you, and this trend is so prevalent that many restaurants, grocery stores, and food products changed their labeling for consumers to more easily identify gluten-free items. But what is gluten, and who should avoid it? What do we advise our clients?

What is gluten?

Gluten is the main protein of wheat, barley, and rye. It is a mixture of a number of related yet distinct proteins, mainly gliadin and glutenin, referred to collectively as “gluten.” It is heat resistant, acts as a binding and extending agent in dough (“glues” things together), and is commonly used as a food additive to improve texture, retain moisture, and enhance flavor.

Gluten is indigestible in humans, largely unresponsive to gastric, pancreatic, and intestinal proteolytic digestion (the breakdown of proteins into smaller polypeptides or amino acids), and has been linked to a number of autoimmune diseases, most notably celiac disease1.

What is celiac disease?

Celiac disease (CD) is a digestive disorder that causes damage to the small intestines. It is triggered by consuming gluten-containing foods. Because of the damage it causes to the small intestine, there is an increased risk of nutrient deficiencies and osteoporosis in the long term and it is linked with other autoimmune diseases2.

The small intestines are lined with finger-like projections, called villi, that aid in the absorption of nutrients. These villi increase the surface area of the intestines and also form a barrier to help regulate what passes through the intestinal wall and into the body.

Gluten can damage, or even destroy, these villi, which will compromise the body’s ability to absorb nutrients and regulate what can pass through that membrane. This condition is known as intestinal permeability, or “leaky gut”.3 Because of this compromised intestinal barrier, molecules that would normally be denied entry are able to pass into the bloodstream and end up anywhere in the body4.

If this happens, the immune system can go into overdrive and attack the molecule and the body’s own tissues to which the molecule is attached, thus creating an autoimmune response. Many people with CD experience gastrointestinal symptoms, though CD may present with non-digestive symptoms.

The symptoms of CD include, but are not limited to:

Anemia, anxiety, bloating or gas, constipation, delayed growth in children, depression, diarrhea, discolored teeth, fatigue/tiredness, headaches or migraines, infertility, irritability, itchy skin rash (dermatitis herpetiformis), joint pain, pale mouth sores, poor weight gain, tingling/numbness, liver disease, non-Hodgkin lymphoma, muscle cramps, osteopenia, infertility, late menarche/early menopause, miscarriage, cerebral ataxia, concentration or memory problems, dementia, mood swings, peripheral neuropathy, seizures, rheumatoid arthritis, Hashimoto’s disease, Crohn’s disease5.

Physicians can use blood tests to detect antibodies in the blood as a way to diagnose Celiac Disease. As many as 1 in 141 Americans may have CD, but most are undiagnosed6.

But the test for celiac disease was negative

Part of the rise in popularity of a gluten-free diet is the relatively new condition of non-celiac gluten sensitivity (NCGS). First described in the late 1970s, and later defined in 1986, NCGS describes individuals who cannot tolerate gluten and experience symptoms overlapping those with Celiac Disease, yet lack the antibodies and intestinal damage seen in individuals with CD.

Their symptoms generally resolve with the elimination of gluten from their diet5. Because of the range of possible symptoms, and sometimes the vagueness of them (mental fog, mood swings, stomach pain), it is often difficult for physicians to treat a patient effectively.

There are a number of patient stories that involve having chronic pain undiagnosed, misdiagnosed, or inadequately treated because there are currently no established criteria for diagnosing non-celiac gluten sensitivity7,8

How do I know if I should eat gluten?

If an individual suspects that he or she may have non-celiac gluten sensitivity, the easiest way to test for it is by implementing an elimination diet. An elimination diet requires the removal of a particular food – in this case, gluten-containing foods – for thirty to sixty days, and then reintroducing it to help determine if that food may be responsible for the presence or exacerbation of symptoms8.

If symptoms resolve with elimination and then reappear with reintroduction, that can serve as evidence that gluten may be a significant contributing factor to an individual’s chronic ailments. With this information, an individual can determine how often to include gluten-containing foods in their diet, if at all.

Fitness Nutrition Coach


1. Biesiekierski JR. What is gluten? J Gastroenterol Hepatol. 2017 Mar;32 Suppl 1:78-81. doi: 10.1111/jgh.13703. Review. PubMed PMID: 28244676.

2. Murray, J. A., MD (Ed.). (2016, June 01). Definition & Facts for Celiac Disease. Retrieved from www.niddk.nih.gov/health-information/digestive-diseases/celiac-disease/definition -facts

3. Arrieta, M C, et al. “Alterations in Intestinal Permeability.” Gut, BMJ Group, Oct. 2006, www.ncbi.nlm.nih.gov/pmc/articles/PMC1856434/.

4. Fasano, Alessio. “Zonulin, Regulation of Tight Junctions, and Autoimmune Diseases.” Annals of the New York Academy of Sciences, U.S. National Library of Medicine, July 2012, www.ncbi.nlm.nih.gov/pmc/articles/PMC3384703/.

5. Kessler, C. (2015). Gut Grief: The Truth About Gluten Sensitivity. Clinician Reviews, S30-A34.

6. Rubio-Tapia A, Ludvigsson JF, Brantner TL, Murray JA, Everhart JE. The prevalence of celiac disease in the United States. American Journal of Gastroenterology. 2012;107(10):1538–1544.

7. Rostami, K., Hogg-Kollars, S. “Non-Coeliac Gluten Sensitivity.” BMJ, British Medical Journal Publishing Group, 30 Nov. 2012, www.bmj.com/content/345/bmj.e7982.

8. Brown, A C. “Gluten Sensitivity: Problems of an Emerging Condition Separate from Celiac Disease.” Expert Review of Gastroenterology & Hepatology., U.S. National Library of Medicine, Feb. 2012, www.ncbi.nlm.nih.gov/pubmed/22149581.


David Rodriguez is a graduate of the Personal Trainer Certificate Program at San Diego Mesa College, an NFPT and ACE Certified Personal Trainer, and Certified Fitness Nutrition Specialist. David was inspired to become a personal trainer after losing more than 100 pounds. Having kept the weight off for over a decade, he uses his story to motivate his clients and demonstrate to them that big changes are possible and sustainable. His training focuses on pain-free movement, helping clients find an individualized nutrition plan, and creating a positive mindset. His favorite pastimes are soccer, weightlifting, hiking, cooking, and his dogs. David lives in San Diego.