You've switched from mayo to mustard, and you're cutting back on Coke—yet these aren't foods that you eat every day. That could be why these occasional sacrifices aren't changing the numbers on the scale.
A better way to think about it: "You'll see more impressive results by focusing on changes that are part of a regular routine," says registered dietician Keri Glassman, the author of The New You (and Improved!) Diet. "Consistency is key." For example, if you drink an 8-ounce glass of soda every afternoon, switching to sparkling water could save 700 calories a week. But if you only drink soda at the movies, say, once a month, try to find a smarter substitution (the bagels you pick up on your way into the office, perhaps) with a bigger payoff.