I wonder if this has something to do with the hacker culture, searching for smart (and quick) ways to achieve a result.
Your body is something you can optimize just as effectively as anything else. It's as simple as "eat better food, get more exercise". None of that fad crap, just more fruits & vegetables, less junk food, and a walk around the block once a day at least.
And there are clear benefits to being healthy. For one thing, you're more likely to live longer, so if you've got some kind of life-long goal in mind, some project you want to accomplish before you die, then getting healthy now will buy you time to do that. You'll sleep better, you'll be more rested, you'll be more alert. If you're prone to anxiety or depression, exercise and good diet helps manage that.
Once you get started, it's easy to start meeting new people after a while. Social connections -- the real ones, not Twitter -- are an amazing resource for any freelancer or solo founder.
But if you convince yourself that being the way you are now is part of the "culture" that you want to immerse yourself in, then you're telling yourself a very pleasant lie, and you've effectively demotivated yourself from doing anything about your fitness.
http://www.flickr.com/photos/scobleizer/6292840317/ : how many of the people in these photos from Startup School look obese to you?