What Foods Cause Gas?

The main cause of gas is the bacterial fermentation of undigested sugars in our colon.

Believe it or not, intestinal gas is normal AND healthy. However, certain foods can stimulate a little too much gas for your liking. This list of foods shows the common culprits of gas and flatulence:

  • Dairy. The main cause of gas is the bacterial fermentation of undigested sugars in our colon. Poor digestion of the milk sugar lactose, therefore, makes dairy products a leading cause of gas¹.
  • Sorbitol and Xylitol. Found in sugar-free sweets, these sugars are often poorly digested.
  • Soda. The high fructose in soda can be another culprit².
  • Eggs. If you’re worried about the smell, take another look at those hard-boiled eggs. Gassy odors appear to stem from the digestion of sulfur-rich foods. If you want to dilute the stench, your best bet is to cut back on foods like meat and eggs – hydrogen sulfide is known as the “rotten egg gas” for a reason.
  • Certain grains. 
  • Cruciferous vegetables/beans. Doubling up to provide prebiotic potential, it’s worth trying to keep them in your diet.


  1. Price KR, et al. Flatulence–causes, relation to diet and remedies. Nahrung. 1988;32(6):609-26. doi: 10.1002/food.19880320626.
  2. Beyer PL, et al. Fructose intake at current levels in the United States may cause gastrointestinal distress in normal adults. J Am Diet Assoc. 2005 Oct;105(10):1559-66. doi: 10.1016/j.jada.2005.07.002.
  3. Di Stefano M, et al. The effect of oral alpha-galactosidase on intestinal gas production and gas-related symptoms. Dig Dis Sci. 2007 Jan;52(1):78-83. doi: 10.1007/s10620-006-9296-9.
  4. McEligot AJ, et al. High dietary fiber consumption is not associated with gastrointestinal discomfort in a diet intervention trial. J Am Diet Assoc. 2002 Apr;102(4):549-51. doi: 10.1016/s0002-8223(02)90127-6.

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