Hi, I'm new to the forum and thought I might get a little insight from you guys.

Small introduction (skip to paragraph two for my actual question if you want):

I'm currently 5'6" 145 lbs, had a skinny scrawny youth and ballooned to 170 lbs in college. I recently lost about 38 lbs in an obsession to lose all the fat (specifically facial fat) on my body, which went rather successfully through outrageously low caloric intake, hydroxycut, and cardio. I started weight lifting (for the first time in my life) in February and am very pleased with my strength and muscle gains. Currently supplementing with whey protein and creatine monohydrate.

I'm ready to take it to the next level and go on a weight gaining diet with one small concern. I am practically phobic of body fat. Is it possible to gain mass without fat gain? I've asked around and heard mixed results/accounts. My body seems specifically geared to collect fat in problem areas (ie jowls and lower stomach) and when I was fat I still had bone thin toothpick legs and wrists. I'm currently very lean and relatively ripped, I just fear whether I should expect an unavoidable amount of fat gain regardless of training routine. If so, I don't even know if I'd want to proceed.

I'm assuming most weight gain routines focus on fat/mass gain and heavy training, with an eventual cardio phase to trim back down. I'm also wondering if there are steadier, slower routines out there that minimize fat gain?

Last question, (feel free to answer any), obviously weight gain is geared towards high caloric intake, but does it truly matter how healthy the diet is if I'm not concerned about cholesterol or my arteries? I'd obviously be taking in plenty of protein, but I'd love to splurge on terrible foods (ie: McDonalds) rather than eat 50 billion chicken breasts and Boca burgers.

Thanks in advance for any and all help! I've had a hard time finding information on "fat gain" in these diets and the connotations of "mass gain" or "weight gain" is slightly ambiguous in all my research.