I signed up for this meal replacement drink called Huel. In brief, it disagrees with my tummy just like LOTS of other people. I called them several times asking for help and got no response. I’m now in dispute resolution with Paypal. Don’t buy Huel. It might work for you but if it doesn’t, you’ll have to pull teeth to return it.
Try googling “huel farts” or “huel stomach ache”. Or don’t and just trust me that this is a problem.