How to Turn Your Phone Into the Ultimate Weight-Loss Tool

Your smartphone comes with a ton of features -- but did you know that with a few small tweaks, you can turn it into the ultimate weight-loss tool? The Apple App Store and Google Play Store offer a plethora of apps that can unlock the full potential of your phone and help you get in shape.

"Many of the tools and apps available for your phone are great because they create more mindfulness and awareness, which makes people more likely to make better decisions," says Ashley Barrient, a registered dietitian with Loyola University Medical Center and a certified personal trainer.

So how do you turn your phone into a fat-burning machine?

[Read: What Your Smartphone Can Tell You About Your Health.]

Count calories. Losing weight starts by simply eating fewer calories, Barrient says, which is why it's important to install a calorie-counting app on your phone. "We commonly recommend MyFitnessPal ( iOS, Android), but there are hundreds available," she says. "You can use the app to figure out how many calories you can eat per day and then track your intake and output. You can even use your phone's camera to snap a picture of [a food package] barcode, and the app will automatically deduct the calories from your daily limit."

Shop better. Eating at home can help you cut down on calories, and your smartphone can help you make smart decisions at the grocery store, through apps like Fooducate ( iOS, Android) and Shopwell ( iOS, Android). These apps provide nutritional information and also give foods a letter grade of A to F so you can see how they fit in your diet. "You can use them to make shopping lists and figure out your calories in advance," Barrient says.

Exercise smarter. It's not just about eating better -- your phone can even help you in the gym. "I use the miCoach app ( iOS, Android)," Barrient says. "It tells you your pace and mileage while you're running, and it has a bunch of celebrity voices that will tell you motivating things to keep you going as well." So when you feel like you're hitting the wall, athletes such as Reggie Bush and Andy Murray can give you the encouragement you need to push on through.

Sync up. Your phone works better when it has a partner, so pair it up with a fitness tracker to maximize its potential. "Fitbit and other fitness trackers are great to add to your workout because they hold you more accountable for what you are, or aren't, doing," says Meg Sheetz, president and chief operating officer of the meal replacement plan company Medifast. "They make it effortless to track your habits, as they transfer all the information directly to your phone." Many of these devices can sync with your calorie-counting app and automatically deduct the number of calories you burn from your daily total.

[Read: Making the Most of Your Fitbit.]

Get connected. Your smartphone is connected to the Internet -- so utilize that, Sheetz says. " You need support to really lose weight," she says. "Just entering your information into an app does a great job of showing you your progress, but if you're not surrounding yourself with people who can help and hold you accountable, it's easier to fall off." You can use social media apps, such as Facebook, Instagram and Twitter, to connect with trainers and other people trying to achieve similar goals to get new tips, tricks and stay motivated.

Have fun. Getting healthy doesn't have to be a chore. Apps like Zombies, Run! ( iOS, Android) turn exercise into a game by using your phone's GPS to show hordes of zombies around you that you need to run away from, adding some excitement to your workout. Other apps like Fitocracy ( iOS, Android) turn working out into a game where you reach new levels by completing reps and sets.

Sleep tight. Did you know your phone can help you shed pounds while you sleep? "There are many apps that track your sleep, which is key to weight loss," Barrient says. "People who are not getting as many hours of sleep are going to have a difficult time losing weight. When you don't get the proper rest, your body isn't properly fueled for the next day. Plus, when you're not well-rested, you tend to eat worse, too." Some sleep apps you can try include Sleepbot ( iOS, Android) and Sleep Cycle ( iOS, Android).

[Read: 10 Ways to Get Better Sleep (and Maybe Cure Your Insomnia).]

While Sheetz personally uses MyFitnessPal and a Fitbit, she says there is no app that is one-size-fits all. "The best app," she says, "is the one you're going to use consistently."

Amir Khan is a Health + Wellness reporter at U.S. News. You can follow him on Twitter, connect with him on LinkedIn or email him at akhan@usnews.com.