I don't know if you guys have Trader Joe's in your area (I'm used to it being everywhere) but they have chunk tuna in olive oil, which works great for omelets because you don't have add any extra oil to the pan and guess at its calories. Plus, it tastes great, though IMO it would diminish the flavor if you made it without the yolks (egg white omelet).
1) eat real food - more vegetables, moderate meat, moderate fruits, less grains, less sugar, less vegetable oils.
2) exercise - moderate intensity cardio, sprinting, heavy lifting, dedicated stretching and mobility.
3) live - relax, de-stress, meditate.
Disclaimer: I'm not professionally qualified to make any formal recommendations. I've just done my homework and I'm my own guinea pig. All of my data, unless otherwise cited, comes from a sample size of n=1 (me).