If you are not used to consuming a lot of fiber, then drinking a whole Blast at once could make you a bit bloated. I would suggest starting off with smaller servings and continue to drink lots of water between meals.
You may also be sensitive to a certain ingredient in your Blast. This will take trial and error to see what it might be.
Here are a few tips that may help:
https://www.nutriliving.com/blog/feeling-bloated