I spend a lot on junk foods

Well why don't you take healthy food from home? Something like carrot sticks, cucumber, fruits or home made sandwiches to snack on? That should help..That way youd only be buying coffee outside. If your workplace sells fruit juices, buy them instead. They are very healthy as you would already know. Use healthier alternatives to pizza like sandwich without cheese, instant noodles and the like. You get these things called mug noodles from Top Ramen. Just drop it in a mug and add hot water (taken from the coffee vending machine at work) and your snack is ready. You could also keep a box of cornflakes or chocos at work and get milk from the coffee machine to eat them. Really easy. :)

I agree with you that foods in the canteen are expensive. Why don't you buy foods in the market and cook it, bring some to your office so that you can save a lot from your salary.

i know what you mean. its wasting your money and its probably not the healthiest choices either. what you could try to do is make food yourself and bring it to work. or go grocery shopping and load up on some foods that you can snack on. maybe some instant food (but not everyday) would be another alternative