Get a notepad and write down everything you eat and every form of exercise you get for at least two weeks. Don’t try to change anything. (But you will—eating mindfully means you’ll pay more attention to what you eat and how much you eat, and you’ll probably alter it.)
Then look at that and ask, where can I replace expensive, unhealthy foods with cheaper, healthy foods? Where can I spend 5 or 10 minutes more being active?
For instance, if you find yourself buying lunch from the vending machines at work because you didn’t have time to put together a lunch, you might find that buying a bag of raw carrots and keeping it in the fridge at work is a better solution—cheaper over the course of 2 or 3 days, and considerably better for you.
And if you park as far away as you can at the grocery store or the office (instead of jockeying with the other shoppers/workers for the closest parking spaces) you get some walking in. If you get off one bus stop or subway stop before the closest one, and get some walking in that way.