Feeling bloated on keto, in the beginning, is common and is due to your body adjusting to your new diet and the dying off of unfavorable bacteria that prefer carbohydrates as food. Bloating that lasts longer than a few weeks can be due to the preexisting condition hypochlorhydria, also known as low stomach acid. There are simple supplements to alleviate hypochlorhydria and reduce stomach bloating on keto.