Hi welcome to Health care magic forum. As you said Adrinaline increases weight gain as follows, adrenaline
which promotes indescriminate eating, and weight gain. Speaking so logically , you should know that it is a side effect of the drug, and happens only less than 1% of the users.
Decrease in weight is due to adrenaline converts fat into some thing the body can use , which lowers weight. (in your words). It is a pharmacological action and is true in 99% of the cases.
So dont worry about adrinaline it can take care of its actions. thank you.