Some people don't tolerate gluten very well, if at all. Problem is that many of the most commonly consumed grains contain gluten. However, there are plenty of nutritious gluten-free grains available, too. Further reading: https://www.healthline.com/nutrition/9-gluten-free-grains Follow Authority Nutrition: Facebook: https://www.facebook.com/AuthorityNutrition/ Twitter: https://twitter.com/AuthNutrition Google Plus: https://plus.google.com/+Authoritynutrition/posts Pinterest: https://www.pinterest.com/authynutrition/ ---- Don't forget to subscribe on YouTube here: https://www.youtube.com/user/AuthorityNutrition?sub_confirmation=1 Studies mentioned: STUDY 1: https://www.ncbi.nlm.nih.gov/pubmed/15184005 STUDY 2: https://www.ncbi.nlm.nih.gov/pubmed/20673059 STUDY 3: https://www.ncbi.nlm.nih.gov/pubmed/24608948 STUDY 4: https://www.ncbi.nlm.nih.gov/pubmed/25411276 STUDY 5: https://www.ncbi.nlm.nih.gov/pubmed/24431078 STUDY 6: https://www.ncbi.nlm.nih.gov/pubmed/21419317 STUDY 7: https://www.ncbi.nlm.nih.gov/pubmed/24829736