Are There Allergies That Make You Fat?

An allergy is an abnormal physiological reaction to some item or substance that triggers the response. Contact allergies can cause itching and rashes, whereas airborne allergens such as pollen and dust can cause sneezing, runny nose and watery eyes. Insects, pet dander and foods like shellfish are common allergens, triggering allergic responses that range from irritating to potentially fatal. Some allergies can even trigger weight gain and wind up making you fat.

Craving and overeating particular foods may be the sign of a Type B food allergy, according to nutritionist Marilyn Glenville, Ph.D., author of the book, "The Foundation of Health." While a Type A food allergy will cause an immediate, often dangerous, physiological reaction, such as the anaphylactic response often generated by allergen exposure in people with shellfish or peanut allergies, Type B food sensitivities can cause more long-term, delayed reactions, including weight gain, fatigue and aching joints, Dr. Glenville reports. Delayed food allergies may not cause an inflammatory response until three days after ingestion, and continuing to eat the triggering food can cause cumulative effects. Current food allergy testing techniques can help identify many Type B food allergies, as can eliminating foods one by one from the diet for an extended period of time.

Common hay fever, pollen, dust and pet dander allergies can make you fat—not because the allergies themselves cause weight gain but rather due to the over-the-counter and prescription antihistamines commonly used to treat the itchy red eyes and runny noses that characterize these allergies. Chronic use of antihistamines increase the appetite and particularly create cravings for carbohydrates, reports Drs. Camelia Davtayan and Mina Ma, of the UCLA Department of Medicine. Antihistamines are so effective at increasing hunger that they are prescribed to anorexic patients as an appetite stimulant. If ongoing daily allergies require you to engage in chronic antihistamine treatment, consult your doctor regarding potential alternative treatments with lower weight-gain effects.

Gluten sensitivity, or grain allergy, in its most severe form comprises celiac disease, which creates serious health impacts, including unintended weight loss, and requires lifelong abstention from wheat, rye and barley products, advises Dr. David S. Klein, practicing physician, author and medical director of The Pain Center of Orlando, writing for DearPharmacist.com, an online natural health information resource. However, only a small percentage of people with gluten sensitivity demonstrate this classic clinical presentation, Dr. Klein states; many more individuals with gluten sensitivity have episodic stomach cramping, bloating and weight gain. Fatigue and joint pain are also related to gluten sensitivity and can lead to additional weight gain by discouraging vigorous physical activity.