Let's begin with the bottom line. Most courts are lining up with the following holding from Morriss v. BNSF Railway Company (8th Cir 04/05/2016):
"In sum, we conclude that for obesity, even morbid obesity, to be considered a physical impairment, it must result from an underlying physiological disorder or condition. This remains the standard even after enactment of the ADAAA, which did not affect the definition of physical impairment."
Melvin A. Morriss, III applied for a machinist job with BNSF Railway, and BNSF extended a conditional offer of employment. Because the position was safety sensitive, however, the offer of employment was contingent on a satisfactory medical review.
Morriss filled out a questionnaire, saying he was 5’10” tall and weighed 270 pounds. BNSF doctors conducted two examinations. At one he weighed 285 pounds and had a body mass index (BMI) of 40.9; at the other, he weighed 281 pounds and had a BMI of 40.4.
BNSF's policy was to not hire anyone for a safety-sensitive position whose BMI was 40 or more, so the employment offer was revoked.
Morriss sued, claiming that BNSF discriminated against him when it revoked its offer of employment based on his obesity. He claimed that (1) his obesity was an actual disability under the ADA and (2) BNSF regarded his obesity as an actual disability. The trial court granted summary judgment for BNSF on both claims, and the 8th Circuit affirmed.
Morriss was unable to establish that he was discriminated against because of a "disability," which the ADA defines as:
“(A) a physical . . . impairment that substantially limits one or more major life activities . . . (B) a record of such an impairment; or (C) being regarded as having such an impairment.”
So what's a "physical impairment"? The ADA doesn't define it, but the EEOC does:
“[a]ny physiological disorder or condition, cosmetic disfigurement, or anatomical loss affecting one or more body systems, such as neurological, musculoskeletal, special sense organs, respiratory (including speech organs), cardiovascular, reproductive, digestive, genitourinary, immune, circulatory, hemic, lymphatic, skin, and endocrine,”
The 8th Circuit reads this as meaning that "for obesity to qualify as a physical impairment — and thus a disability — under the ADA, it must result from an underlying physiological disorder or condition." And this is true even if one's weight is far outside the normal range.
As for Morriss, the medical evidence indicated that he did not have an underlying physiological disorder or condition.
Two other federal courts of appeal have reached this same result: EEOC v. Watkins Motor Lines, Inc., 463 F.3d 436 (6th Cir 2006); Francis v. City of Meriden, 129 F.3d 281 (2d Cir 1997). (These are pre-ADAAA cases, but the definition of "physical impairment" was not modified, so the 8th Circuit considers these cases to be good law.)
On the other hand, the Montana Supreme Court has concluded that “Obesity that is not the symptom of a physiological disorder or condition may constitute a ‘physical . . . impairment’ . . . if the individual’s weight is outside ‘normal range’ and affects ‘one or more body systems.’" BNSF Ry. Co. v. Feit, 281 P.3d 225 (Mont. 2012). But the 8th Circuit says that "an individual’s weight is generally a physical characteristic that qualifies as a physical impairment only if it falls outside the normal range and it occurs as the result of a physiological disorder."
Oh yes, Morriss pointed to the EEOC Compliance Manual, which says that "severe obesity" (i.e., more than 100% over normal body weight) can constitute an impairment even without an underlying physiological disorder. The 8th Circuit trashed this argument on two grounds. First, the Compliance Manual "directly contradicts the plain language of the Act, as well as the EEOC’s own regulations and interpretive guidance." Second, Morriss's normal weight was 199.5 pounds [I'm impressed with this kind of precision!], so he would need to weigh at least 399 pounds in order to double that, and he actually weighed in at 281-285.