The video starts off simple, with the guise of presenting tips to losing weight before hitting you with a curveball: "Step 3: Get Your Heart Broken." And this is when the meat of the short commences.
We see our main character (Beck Bennett from SNL) struggle through the break-up, pushing back his feelings, hitting the gym daily, and eventually getting over it, even when suffering through the woes- all done with chirpy narration because it is taking the form of a self-help guide. The result is something genuinely funny while also playing with your emotions. Sure, the comedy can get subdued, but it's all in the touches and how Beck's character deals with his world collapsing around him before attempting to reconstruct that keeps it functioning.
There's not too much to write about this one that hasn't already been said and can't be explored further without watching it. I guess the biggest question is why I would include it among a varied list of things almost distinctly pertaining to the Internet. Granted, this isn't from a TV show like SNL, but it's still an independent production, and the channel that posted it, buh, is itself a platform for the world's top comedians (as it proudly flaunts). This isn't amateur work. Heck, Conan pops up in it.
Ultimately, though, it just boils down to its sheer poignancy. Making a short like this is incredibly difficult, yet "How to Lose Weight" did it in flying colors.