I have a gym about 5 minutes from work, and I hit a 30 minute workout. with travel, changing clothes, and showering, I can be back in less than an hour.
I used to regularly go to the pizza buffet place for lunch and when the employees all started recognizing me and making my favorite pies as soon as I walked in, I realized I needed to make a change. So I started going to the gym then instead, which had the multiple benefits of eating less junk food, saving money, and working out.
It was a little weird at first since it's not a normal work out time, but now it's been like 10 years and it's just a normal routine for me.
I keep fruit, peanut butter, and protein bars at the office to have something to eat other than a full lunch.