Lose Weight With Your Phone

En español | Smartphones are spreading fast throughout American life, and we're now using them to slow our own spread, too. Calorie counting has never been easier. Powerful handheld computers can quickly calculate the nutritional value — or lack thereof — of our favorite foods and track it over time.

See also: The simplest, cheapest weight-loss trick ever.

Simple phone apps help you count calories. — fStop/Getty Images

The apps are easy to learn and use. Some only need the snap of a photo or the scanning of a bar code to do their work. None requires us to do more than lift a finger, though most also encourage and can track exercise, as well.

While workouts have a lot of health benefits, if you want to lose weight, your focus should be on cutting calories, so we've selected apps for evaluating food with this goal in mind.

Portability is the power added to this new wave of software. Although most permit you to also track your calories on a website, now you can enter key information on the go, or maybe while stopped, waiting for the food order to arrive. That's what makes these apps the best thing for weight loss since (thinly) sliced (whole-grain) bread.

Lose It!

True to its iPhone roots, this app has a streamlined, simple look and feel. That means less time fumbling to enter the calories you've consumed. The software so far has no ads or pitches for paid upgrades, a refreshing change from many competitors. Punch in a weight-loss goal, perhaps a pound a week, and Lose It! calculates a daily calorie budget. In a friendly twist, unused calories accumulate through the week to authorize a weekend splurge. If desired, Lose It! will share progress with friends via Facebook, Twitter or email. Its somewhat limited database of foods is skewed toward processed and restaurant foods, so you may have to add custom eats more often than with some other apps.

Available for: iPhone, Android version promised
Price: Free

MyFitnessPal

This powerful and versatile app is not as easy to use as some. But with more than 750,000 entries, it has perhaps the largest listing of foods. It's also one of the more comprehensive apps, particularly on Android, where it even includes a bar code reader (promised soon for iPhones). Scan the bar code on a cereal box or even a bag of apples and the program returns the nutrition data. MyFitnessPal also can share your progress with friends, and is unique in letting you add multiple foods at once to your journal. On the downside, ads litter the Android app and the accompanying website — it's jarring to see a pitch for Taco Bell atop health tips.

Available for: iPhone, Android and BlackBerry
Price: Free