It can also track exercise, although I've opted to track it in notes vs. through their exercise (calorie burning) database: the reason for this is because say you go running for a couple hours and burned around 200 calories - the site then gives you a 200 calorie extra allowance in your daily food intake.
So by not officially reporting the exercise, I am eliminating the extra allowance and sticking to my set calorie goal on a daily basis. I'm tracking sugar and fiber much better, which is tremendously healthy awareness. I've made strides at weight loss that I haven't made in over a year, and it's been really great.
MyFitnessPal - Free Calorie Counter