I weaned myself off of Coke by switching to Coke Zero then to water/tea/coffee with a sprinkle of a packet of sugar for taste.
Don't mindlessly eat at your desk. It's unsanitary and has been proven to cause people to eat more than they would consciously.
When you skip a meal, don't cave to your body's urge to eat double next meal. You will just send it straight to fat. Remember when you skip meals, then carefully portion the next meal to avoid the set back.
A good low carb, medium-low fat, high protein shake with lots of vitamins is a great way to skip a meal, maintain muscle mass, and avoid the insulin/cortisol cycle that drives fat storage. These shakes should be enough to discourage you from partaking in the temptation around you.
If the shakes aren't enough try celery, carrots, fresh fruit (not dried more on that later), and other low carb foods.
Never keep dried fruit around, it's too calorie dense for our own good. Would you eat 24 apricots? No? Then why are you eating 24 dried apricots?
I still don't bring lunch but I avoid pizza, taco bell, burgers, etc. Small bento box with lots of salad and no fried stuff. BBQ without any biscuits/bread. Rotisserie chicken with steamed vegetables. Protein shakes.