Step1
Wash an apple (or other seasonal fruit) and take it with you to work everyday. When you crave a sugary snack it will be on your desk waiting and easy. In fact, much easier than going to the vending machine. In time you'll find yourself craving the fruit instead of your default snack of the past. Low fat popcorn (or unsalted nuts if you have high blood pressure) is a good substitute for fried salty snacks.
Step2
Now that a healthy snack is a habit, let's add a second habit - water. It's amazing how enough water can make us have more energy. Most of us are dehydrated. They say to have 8 glasses a day, but you can temper that with other juices, and even soups that you have throughout the day. I count every liquid that doesn't contain caffeine.
If you are a coffee drinker, bring a glass for water to work with you, and fill it up every time you get a coffee. (That means downing the water before you get your next coffee too!) If that doesn't work, you can always schedule it in your calendar (google calendar will even text your phone) - and have a reminder every other hour that it's time to get another glass.
Step3
This step will take a little time, but less time than it takes to go out to eat for lunch. Most of us don't have a whole foods or a co-op near by, so we rarely have a multitude of healthy choices for the lunch. More often it's a Chinese, Indian, or pizza buffet and they hide tons of fat, salt, and sugars.
So now we are going to pack a salad everyday to bring for lunch. You can eat it and still enjoy a smaller portion of the food you are used to -or- you can also bring some soup for a frugal nutritious meal.
First go to the grocery (or farmers market) over the weekend and get some baby lettuce, baby spinach, or a pre-washed blend. Next find a crumbly cheese such as goat or feta, then go to the bulk aisle and grab a handful of nuts (pecans are my favorites) and a few dried cranberries. Now go to the dressing section. It will be a little confusing - my recommendation is Newman's Lighten up Balsamic Vinaigrette, it tastes great and has very few calories.
The night before work throw some of the greens in a large lidded container (ziplock, glad, or pyrex all work fine), top with a small handful of crumbled cheese and top with a sprinkling of nuts. Either bring the dressing bottle with you to work (since this will be your daily salad) or in a tiny lidded container.
Step4
Once you have incorporated these new steps towards health, you'll wonder what all the fuss was in the beginning. What seemed out of reach before, is now a matter of habit. From here you have a whole world of food options ahead of you. Look for some low fat recipes on the web. One of my favorites is www.fatfreevegan.com - I know it may sound odd, but there are some easy, tasty and healthy dishes waiting for you to try them.
Good luck on your journey to take better care of yourself!