However valuable their service, they're not perfect. I, of course, don't expect them to be, but, as a math major, I can't help ribbing them about this one. This is the diet score card, which I find to be one of the most important parts of their site.
As you can see, it's a sort of dashboard for your daily dietary intake. You can track pretty much any nutrient you want (through use of the "More" button you see in the lower right), the three macronutrients in particular; I'm sure you've noticed the percentages below each of them, clearly intended to give you an idea of how well you're maintaining your chosen balance. Nice, huh?
The problem is that they don't make any gods damned sense. 37g of fat is not 34% of either 42 or 51. Nor is it 34% of the combined total of the macronutrients. Nor is it 34% of my overall nutrition intake by weight. At least they add up to 100%, which wasn't always the case, so, y'know... thank the gods for small miracles.