Fat discrimination is rampant in education, health care, and employment. Antiobesity activists claim that it is not only acceptable, but actually desirable to stigmatize fat bodies because this stigmatization shames fat people into better health. In response, the fat acceptance movement turned to science to show that fat bodies can be healthy. As part of this movement, legislative advocacy and litigation strategies have utilized the argument that fat discrimination should not be permitted because fat people can be healthy. I argue that this move undermines the true justice that the fat acceptance community seeks. In the quest towards the fat acceptance movement’s ultimate goal of acceptance for all fat bodies, the movement must demand dignity and respect for all bodies, including fat bodies that are unhealthy. In this Note, I will discuss the theoretical problems inherent in the two most frequent arguments employed by fat able-bodied plaintiffs: that they are healthy in comparison with unhealthy or disabled people, and, alternatively, that they are disabled. In addition to being theoretically problematic, as a practical matter, fat discrimination challenges using claims based on the good health and able bodies of fat persons have been mostly unsuccessful. On the other hand, some contemporaneous fat plaintiffs have won cases in which they claimed that fatness is a disability. I argue that fat plaintiffs who use disability claims must work in solidarity with the disability rights movement, which demands respect, self-determination, and access for disabled people. If they do not, fat plaintiffs risk creating precedent that will make it harder for disabled people to prove their own discrimination claims and perpetuating stereotypes about disabled people. In all cases, as an anti-oppression movement within a broader social justice framework, the fat acceptance movement must work in solidarity with the disability justice movement rather than undermining the legal protections disabled people have won.