Originally Posted by gregf83

For most people riding in an optimal aero position their legs are close to their chest and stomach adding a couple extra inches to their waist and chest is clearly going to have an impact on how low they go. Maybe if you're riding around on the tops or hoods it won't matter as much but you still won't put out as much power with an extra 50lbs of fat so you'll be slower.

There's a reason TT champions aren't fat.