i would check with your doctor first to be safe
You should probably talk to your dr about this. Really any diet plan you try should be discussed with your dr, but who actually does that? Not Me!!
The problem here though is taking some sort of supplement/medicine and if it will react with any asthma meds you are taking. Interactions there or if you are allergic to an ingredient could be an issue.
I have never take supplements/medicines. I have used Slim Fast though.
I hope you do find something that will sucessfully get you to your health goals.
Take care.