I try to stay away from Fats as much as possible and of course there are types of fats. The good fats that you want come from fish, chicken, nuts, etc.. Fish oil is my favorite, so I stick to real chicken for my omegas and I am satisfied. If you are on a diet, stay away from the bad stuff, saturated fats, and all the cholesterol.
Since I switched to vegetables and fish fillets, it's incredible how my stomach feels! It feels light, NEVER BLOATED, which means I am super confortable at the gym while running or lifting. It's awesome 100%. Before when I ate junk a lot, I would get there feeling "FULL" and sometimes not having energy. Now that I do cardio, I feel energetic all the time and I sweat a lot when lifting--I love it :P