Pondered in the NFL locker room this season, as some players try on their new tighter, sleeker Nike uniforms, is a question usually reserved for Nordstrom fitting lounges: Does this make me look fat?

"I hate them. They are built for thin guys," said Alex Boone, a 300-pound starting guard for the San Francisco 49ers. "It makes me look like I have big old love handles."

After...