I may have some input here, but it'll differ with what a lot of people on the forums. I don't like 5x5, I think its flawed in the specs, but the general theme or foundation is awesome - that is, heavy weights in core compound lifts, low reps, and intense full body workouts 3x a week.
Not too long ago I had a 40 inch waistline, and I WaS in great shape before, but got lazy. I started my routine which was 3 full body work outs a week with random HIIT sessions on off days when I felt like it. Every 4 weeks I switched to a bb 5 day split routine, then went back to the full body routine.
In 6 to 8 months, somewhere around there, I dropped to size 33ish waistline, I increased my core lifts immensely. I didn't count calories, didn't take supplements except pre workout and my diet was whatever. I ate 3 times a day, sometimes twice, and had pizza, burritos and fastfood very often. I didn't get a six pack but trust me, I looked damn good relatively speaking.
What's my point? If you lift HEAVY, if u do HIIT (not boring 45 minute jogs) and just be overal intense when u train, ur bodys gonna turn into a 24/7 fat burner. Squat, row, bench, dead as heavy as possible, sprint like ur running for ur life, and ur gonna burn fat. And I'm not an ectomorph, my metabolism sucks balls if I'm inactive. I'm not advocating eating pizza and crap like I did, I'm just saying u can get amazing results with whatever routine you choose as long as the foundation is built around hight intensity compound movements and hiit.
Look at michael phelps, he eats pretty shitty, he doesn't have a bodybuilder look, but he's definitely not fat either