Does eating magic mushrooms cause you to lose weight?

No. "magic mushrooms" is what most people call hallucinogenic mushrooms, which have psilocybin as their most active component. I believe my colleague is speaking of another kind of mushrooms other than these hallucinogenic ones. Used recreationally, "magic" mushrooms can produce anxiety, panic, and even psychosis. Psilocybin content is unpredictable in these. They are not a weight loss aid.
Yes. It helps by cleaning liver - ganoderma lucidum is highly-regarded for its medicinal properties that help improve human body’s healing ability while helping its user to maintain good physical shape. Aside from promoting longevity, ganoderma lucidum has unique properties that contribute much to the strengthening of the immune system. Somewhat rare in the west is also known as reishi mushroom.