Make a lunch bag with healthy food. Healthy snacks that you can eat every once in a while to keep your blood sugar level steady and your metabolism going. Have a full glass of water nearby at all times.

I didn't quite get the part where you explain when you eat and what you eat...So I don't know.

If you cannot workout after work ,then maybe before work?
Honestly there aren't many options unless you start getting to work with a bicycle.