Losing those extra holiday pounds doesn't necessarily mean committing to a major diet program. You can lose a pound a week by just making some minor changes in your food choices, and that can add up to a net loss of 12-15 pounds between New Years and bathing suit season.

The basics are irrefutable: the body requires 3500 calories to create or maintain a pound of body weight. If you reduce your calorie consumption by 500 a day, in seven days you will have a 3500 calorie deficit and that translates to the loss of one pound. Do it for a month and you'll lose 4 - 5 pounds - and because you took it off at a safe and steady pace, doctors say it's more likely to stay off.

Here are three small and simple substitutions that can make a big difference without being a big deal.

1. Go Pre-Packaged. Recent studies prove what snackers already knew anyhow: the odds that you'll actually measure out a perfect portion of chips or crackers are low indeed. The bigger the bag, the more we eat. But that doesn't mean you have to entirely forego your afternoon snackfood fix. Investing in some 100-calorie portion packs can pay big dividends in calorie savings.

A regular size bag of butter flavored microwave popcorn can weigh in at a whopping 350 calories or more. If you switch to a hundred-calorie pack, you'll satisfy the cravings while banking 250 calories. If you also substitute a 100-calorie pack of mini-cookies for your coffee-break doughnut or Danish, you've saved at least 250 more.

2. Drink Smarter. It's easy to forget that the calories we drink are every bit as fattening as the ones we eat. If you're a soda fan, just switching from regular to diet can save you at least 100 calories per can, and a lite beer instead of a regular can trim 80-100 calories from your intake.

Coffee counts too, or at least what we put in it does. Switch from cream and sugar to a powdered creamer and zero-calorie sweetener and you could be saving yourself 100 calories a cup! Making good choices on just beverages alone can easily lop 500 calories off your daily intake.

3. Look for Low Fat. Save 250 calories at breakfast by simply choosing skim rather than full-fat milk and using fat-free spread rather than butter on your toast. For lunch, choosing low-fat rather than regular mayo will knock a full hundred calories out of your sandwich, and if you make it with low-fat cheese you can deduct another 50 calories per slice.