Don't call someone fat. Be nice, and call them portly. Portly is just one of several words that are kinder than "fat," including "stout," "heavy," and "pleasingly plump."
The tenor was portly, but all that girth makes it easier for him to produce all that sound. One way to remember the meaning of the word portly is to think of a bottle of port, the sweet wine that tastes like sherry and is notoriously calorific. Want to be less portly? Then try drinking less port and other alcoholic beverages.
