According to this source: http://www.personneltoday.com/Articles/2005/10/25/32213/obesity-research-fattism-is-the-last-bastion-of-employee.html
%12 of HR officers think obese people shouldn’t have client facing roles
%93 would hire a person of average weight over an obese person, if the two have identical qualifications
%30 think that it’s fair not to hire someone if they’re obese (I think, considering the above statistic, this would be regardless of qualifications)
%47 think that an obese worker is a less productive worker
and, %11 think that it’s fair to fire someone, purely on the basis of their being obese. (And not say, their work ethics etc.)
According to this site here, there’s a pay gap between employees of an average weight, and obese employees, for two people doing the same job: http://www.usatoday.com/money/workplace/2002-09-04-overweight-pay-bias_x.htm
This site says that there are few legal protections against ‘weightism’: http://www.foh4you.com/mem/library/default.asp?TopicId=313&CategoryId=0&ArticleId=19
This website comes from an employers point of view: http://www.braunconsulting.com/bcg/newsletters/summer2004/summer20043.html
it lists the costs of hiring obese workers, and basically says that obese workers cost businesses money. Given this stance, and these statistics, it seems unsurprising that obese employees are discriminated against.