Are Food Allergies Making You Gain Weight?

by | Nov 4, 2022 | Allergies, Food, Articles, Conditions, Digestive Health, Weight loss

If you struggle with losing weight despite eating well and exercising then consider investigating for delayed food allergies.  Along with hormone imbalance and poor intestinal health we find the connection between food allergies and weight gain to be quite common.  Our clinic tests 6-8 people each week and we routinely see patients losing 10 or 15 pounds in a few months simply by eliminating food allergens.  Over the course of a year many patients will lose as much as 20-30 pounds.

But “I don’t have food allergies”, you may say.  Actually, most people probably do and just don’t know it.  The reason is that we are talking about “delayed” versus “immediate” allergies.  Many practitioners refer to these allergies as “sensitivities” or “intolerances” but in fact anything that triggers an abnormal immune reaction is an allergy.

When speaking of allergies most doctors and patients alike usually think of the immediate allergy reaction involving an antibody called IgE and histamine.  This reaction happens in seconds to minutes to a few hours and is the reaction seen with hives and hayfever type allergies.  And it can happen with foods as well causing fairly quick reactions such as hives, throat tingling or swelling, abdominal pain, vomiting or diarrhea.  Severe immediate food allergies, such as with peanuts, may result in anaphylactic shock which is life threatening.

The delayed food allergy response is sneaky and difficult to recognize.  The antibody involved is IgG and the reaction generally takes 12-72 hours to really get going.  The immune reaction occurs just outside the lining of the gut where about 80% of the infection fighting lymphocytes are produced – in the “gut associated lymphoid tissue” or GALT.

When the GALT is provoked numerous chemicals called cytokines are released and travel throughout the body causing inflammation and various symptoms.  Most common are chronic sinus congestion, indigestion, irritable bowel syndrome, fatigue, and brain fog.  Less common but still routine are things such as anxiety, depression, insomnia, asthma, headaches, racing heart, rashes, and joint pains.  Research has clearly shown how the cytokines will disrupt hormone and neurotransmitter systems.  The delayed food allergy response has also been linked to “triggering” autoimmune diseases by overwhelming the regulatory part of the immune system.

So what about weight gain?

How in the world does an allergy contribute to putting on weight?  First of all, many patients are craving the very foods they are allergic to.  Sugar and high-glycemic foods, including common allergens such as wheat and corn, will initially stimulate the “feel good” neurotransmitter in the brain called serotonin.  This is familiar to anyone who “eats for comfort” and knows the temporary good feeling that comes from eating certain foods.  The effect doesn’t last long however and leaves people craving again.  Added to this is the allergy effect – the inflammatory cytokines eventually cause a decrease in serotonin which compounds the whole issue of cravings.

The second connection between food allergies and weight gain is the anti-inflammatory hormone called cortisol.  The body naturally makes cortisol to control inflammation.  Unfortunately cortisol also increases blood sugar and with chronic food allergies the persistent inflammation will stimulate ongoing cortisol production leading to persistent blood sugar stimulation.  Now the body makes more insulin to control the sugar and before long insulin resistance and diabetes take hold.  Cortisol also causes fat to accumulate around the midsection leading to an “apple” shaped body.

A third cause for weight gain with food allergies is the lack of nutrition that can result from an inflamed gut and an overworked immune system.  The inflammation at the gut wall, often combined with a lack of beneficial bacteria in the gut, can lead to deficiencies in nutrients that are essential for proper metabolism and weight control.  Furthermore, the immune system needs nutrients to operate effectively, so the chronic activity involved in fighting the immune reaction to foods uses a lot of nutrients in just trying to keep up.

Testing for delayed food allergies

Testing is done through a simple blood test.  I’ve used 12 different labs over the years and paid to do “blind” samples to test various labs – the results often show very poor reproducibility and proved to me that many good commercial labs do not do food allergy testing very well.  Our favorite lab for food allergy testing, Immunolabs, has about 90-95% reproducibility in our studies and our patient outcomes reflect this.  We also use Cyrex labs to test for leaky gut and many different food panels.

Skin testing and RAST blood testing for food allergies is looking for the immediate IgE reaction, which is just fine – but again, most people usually figure out these type of allergies since the reaction is quick and thus the offending food recognized.  We rarely do this type of testing, but typically it is done when a patient notes symptoms within minutes to a few hours after eating.

Many allergy specialists and allergy organizations do not put much credence into delayed food allergy testing and can partly I understand why.  First, the variation in most labs’ results would indeed give studies on delayed food allergies poor outcomes.  Second, there is much more to food allergy treatment than simply removing the offending foods.  The other necessary part of treatment involves “healing the gut”.  If the gut is inflamed, leaky, lacking beneficial bacteria, or infected with pathogens such as candida or virulent bacteria, then removal of food allergens will lead to a partial improvement at best.

All patients in our practice, and especially in our weight loss programs, are encouraged to undergo digestive health analysis and food allergy testing.  Stool testing reveals abnormalities in the gut, while blood testing is done for the food allergies.  Our standard blood panel tests for 88 foods and may include testing for gluten allergies and celiac disease.

Even without formal testing it is reasonable to try some empiric treatments.  We often start patients on specific blends of probiotics, l-glutamine, fiber and multi-vitamin-enzyme formulations.  The most common food allergens are wheat, dairy, egg, corn and soy.  A simple elimination-challenge diet is to try avoiding each for a month (elimination), then reintroduce that food twice per day for 3-4 days (challenge), and monitor what happens.

Having provided food allergy testing for over 20 years I continue to be amazed at the outcomes with the elimination of food allergens.  I’d estimate 70-80% of all patients tested report positive results, with at least 20-30% reporting “amazing” results.  For many it was the key to helping them lose weight.


Scott Rollins, MD, is Board Certified with the American Board of Family Practice and the American Board of Anti-Aging and Regenerative Medicine.  He specializes in bioidentical hormone replacement for men and women, thyroid and adrenal disorders, fibromyalgia and other complex medical conditions.  He is founder and medical director of the Integrative Medicine Center of Western Colorado ( and Bellezza Laser Aesthetics (   Call (970) 245-6911 for an appointment or more information.

Print Friendly, PDF & Email

Thanks for sharing this article!