As the name suggests, MyFitnessPal is a community-oriented site designed to help you lose weight and track fitness goals. The mobile apps let you keep these features at your fingertips wherever you are. You can input or edit your goals, enter your caloric intake (food) and output (exercise) on the go, and add new food data to the library if it doesn't already exist. There's also a progress screen that lets you track your weight and view a graphical representation of how well--or poorly--you're doing.
To test the mobile bent of the service, we downloaded the associated iPhone app and gave it a whirl. After having used Lose It for an extended period of time, we're not particularly fond of the interface for MyFitnessPal. One issue--a minor one--is that it's not as visually appealing as Lose It, which offers little icons for the majority of the food items in the library. More of a problem for some will be the tiny writing that populates the search screen, as it creates a bit of eye-strain to read the multitude of options that are presented. On the whole, we found that MyFitnessPal's interface is less polished than that of Lose It. We do, however, appreciate the multiadd function, which lets you add several foods at once; a time-saver for anyone who eats similar meals from day to day.
On the plus side, MyFitnessPal offers a community aspect not offered by the other app, as well as a dedicated Web site with a variety of handy tools. There are calculators for BMR (basal metabolic rate), BMI (body mass index), and recipe nutritional info (to be fair, Lose It offers this functionality within its app). You can also create a personalized weight loss ticker for your profile, forum signature, or blog. In the end, if you're trying to get fit, pretty much any tool or support is better than none, and MyFitnessPal is free so it's definitely worth a look.