Always, always prioritize your health. Get complete sleep, eat right, and exercise everyday.
If you don't take care of your health now, you'll suffer the consequences later. It won't be good in the long run. Even if it's because you're working extra hours and you're saving for your future—not taking care of yourself now could set you back rather than move you forward.
When your body gives up, you won't be able to work at all. It will bring you back 10 steps or so, and your late nights and working lunches wouldn't matter then.
If your excuse for not taking care of yourself is the many responsibilities you have, then think about this:
When your body gives up, you wouldn't be able to fulfill those responsibilities anyway. It would've been for nothing.
Give your body the fuel it needs to keep going. To crush goals. To give you the success you crave. To take you where you want to go.
Take care of yourself first, then take care of everything else.