look the best thing to do for him is to do a combination of cardio and weight training,the more muscle he has the more body fat he will burn, the negative feedback loop is there on gh but to what extent who knows,it doesnt cause a perminant shut down of gh from what i gather,do some reading up on some of doctari's posts before anything
insulin is used with gh as gh causes the body to become insulin insensitive,that being said u can use things such as alpha lipolic acid,chromium and cinnamon to combat this issue,i think if your friend is vastly over weight using insulin is the last thing on his list...
gh also bluntens your thyroid release aswell hence the reason it is advised to use t3 with gh aswell, but not completely necessary..
if using gh i would go on 5iu's a day for fat loss,i would run him just on the test alone with some arimadex as he might have estrogen related fat issues so keeping him on arimadex will help as well as some proviron, low dose of t3 to start depending on the dosage of test he is using, 600mg of test a week he can get away with 25-50mcg of t3.diet and training is essential for this to happen,it is a long process...but adding muscle is key.
please make sure he gets a fully physical before he even considers starting a weight training and heavy exercise regime!
he might not have to use hcg from 12 weeks onwards if he carries on cycle,he might be elligable for testosterone replacement therapy at his weight,age etc but he will need to go and get bloods done in order to verify this....
gh is very good stuff when used in combination with steroids,on its own its a very expensive fat burner,it helps with the building of lean quality muscle tissue.