Firstly, I'm naturally endomorphic. Building muscle for me is like masturbating, I couldn't stop if I wanted too. That being said, I've maintained a pretty health lifestyle. I HIIT 3 times a week (for about 10-15 minutes minus warm-up, just depends on when I burn out) first thing in the morning without any food, and I do aerobics twice a week for an hour (treadmill uphill walking) and I lift 5 days a week, split body workouts doing 3x12 for the compound movements and 3x15/20 for the more isolated movements. I also do an ab routine every morning before my morning cardio which basically is doing "supersets" of crunches, reverse crunches, and oblique crunches.
On average I take in 140 ounces of water a day, some days more, some days less but 140 is a good average. I try to keep my carb range between 150-200 a day, maybe a little less on the weekends because I don't work out at all. Proteins and fats I don't usually count because of the excess amount of protein and low amount of fat.
Yet despite what I "thought" was the idea lifestyle to get used to, I still find myself not acheiving the lean physique I'm looking for. My limbs are pretty much lean and show pretty good definition, same with my back. My chest and stomach are the areas I'm trying to fine tune but I'm at a loss for a plan of attack. Any suggestions/advice would be appreciated.