Weight Discrimination - As Prevalent as Race Discrimination?

According to a recent study, weight discrimination, particularly against women, may be an emerging form of discrimination in the workplace.  According to the study by The International Journal of Obesity:

"Among obese people, approximately 28 percent of men and 45 percent of women said they have experienced discrimination because of their weight."

There's a long slippery slope with a lot of confusion on whether conduct by an employer in such instances could amount to perceived disability under the American's With Disabilities Act, not to mention more protective state and local laws.