Me, I'm 5'2" and started at 243 pounds. Remember the Weebils toy people? That's pretty close to how I feel I looked like.
Even better, I'm on a recumbent trike, with a husky hitched to the seat frame, ball cap stuffed under the cycle helmet since they don't seem to make helmets with enough of a sun brim. All sorts of laugh factor.
Thankfully, I have a 'lazy' husky and he doesn't pull much past the first 2 miles so I still get plenty of exercise. I'm down to about 218 pounds and regularly do 40+ mile trips. (The husky just did his first 40+ mile trip Saturday and wanted to go again Sunday
) As for shorts, I have the same unwillingness to wear them. Instead, I wear tights with a pair of gym shorts over that since I feel worse than naked with just lycra tights.
And for the record, while I have been laughed at, I've never been laughed at by someone on a bike. From them, I get waves, nods, encouraging yells, smiles, and thumbs up. The non-bikers who do laugh would probably kill themselves trying to do my long trips.