Modern United States clothing is a thin man's, or woman's, game, but this hasn't always been the case; it doesn't have to be the case that the fat are unfashionable. European clothing as late as the 18th century, and especially in the 15th-16th centuries, was designed for a heavier average weight than the current one (and this is without beginning to discuss, for example, traditional Chinese clothing).

I don't know if I'm really crazy enough to recommend that you try dressing like Henry VIII or Benjamin Franklin; but keep in mind that it's hypothetically possible, at least.

(Then again, how much _could_ anyone do to you if you went out to dinner or got on a subway dressed in the best fashions of 250 years ago (other than the Scots Highland style of dress which requires a dagger tucked into the left stocking)? I could see certain sorts of people recommending it as a character- or determination-building exercise...)

More seriously, though, I agree with the idea that Winston Churchill -- or G.K. Chesterton, legendarily overweight but positively dapper -- might be a good starting point.