Can a chain restaurant decline someone a job based on appearance, specifically weight (overweight)?

My boyfriend was declined a baker position at Panera because, as the district manager said "you do not look good enough." He is overweight and part Mexican, but still a very hard worker at the Panera he is at now (in Georgia) - never late, works his off, stays extra hours and helps other people. He does a lot of the baking anyway, but does not have the title of being a baker or the pay/hours. I was under the impression from my old cles that you can't reject someone from a job because of appearances unless it was an appearance-specific job, like modeling, but can't say for sure.