Eating more than one serving of GF food

Katarina Mollo MEd, RDN, LDN
Q:  When eating food labeled gluten free at below 20 ppm per serving ... Am I overloading on gluten by eating more than one serving?


No, it is very unlikely that you would overload on gluten by eating more than a serving. Foods that are labeled gluten free have to contain less than 20 parts per million (ppm) of gluten. Consuming foods at a concentration of 20 ppm gluten is considered safe for those with celiac disease. It is unlikely to cause issues even if you eat a lot of food.

20 ppm = 0.002%

20 ppm = 20 mg/kg


In a study by Catassi et al. they determined that more than 50 mg of gluten per day was harmful for people with celiac disease, but some also showed villous atrophy at above 10 mg (1). Based on this research, the 10 mg threshold is usually used when talking about thresholds for gluten consumption for people with celiac disease.

Using this amount as a reference, you would have to eat 17 slices of gluten-free bread that contains 20 ppm gluten in order to hit the 10 mg threshold.

Check out these two infographics to help you get a good visual overview of gluten thresholds and 20 ppm.


In summary, consuming a diet at 20 parts per million (ppm) is considered safe for those with celiac disease, because it should put most people below the 10 mg threshold when you add up all the foods eaten in a day. There is no need to restrict gluten-free foods.

You can read more about gluten levels and amounts of foods here:


  1. Catassi C, Fabiani E, Iacono G, D'Agate C, Francavilla R, Biagi F, Volta U, Accomando S, Picarelli A, De Vitis I, Pianelli G, Gesuita R, Carle F, Mandolesi A, Bearzi I, Fasano A. A prospective, double-blind, placebo-controlled trial to establish a safe gluten threshold for patients with celiac disease. Am J Clin Nutr. 2007;85(1):160-6.
  2. Thompson T. How much is 20 parts per million? Gluten Free Dietitian Website:,per%2035.27%20ounces%20of%20food. Published February 6, 2008.

Reviewed October 21, 2022.

Note: This information is provided by NCA and Katarina Mollo MEd, RDN, LDN, NCA's Director of Education. This information is meant for educational purposes only and is not intended to substitute for personalized medical advice or replace any medical advice provided directly to you by your health care provider. No liability is assumed by the NCA or Katarina Mollo, MEd, RDN, LDN by providing this information.

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