Honestly, your friend needs to slap the trainer. The trainer does not have his best interest at heart. In all likelihood, your gym "trainer" is probably offering to supply your friend with the deca and test.
I'm not kidding you or being a smart ass at all! I really hope you understand. If your friend is taller than approximately 4'4", then his lb/per inch is below 2.5. It's not a rule of thumb or anything, but less than 2.5lb/inch is getting pretty damn thin for a guy who wants to run gear. I can't see why anybody couldn't make it over 3lb/inch without touching gear.
My point, your friend can't possibly have a clue of how to eat. His trainer is an idiot and only trying to screw him up.