The increasing prevalence of obesity has become one of the most challenging problems facing healthcare providers. Despite recommendations from the US Preventive Services Task Force, many health professionals fail to discuss obesity with their patients. This study sought to identify terms that obese individuals who were treated in primary care would find the most and least acceptable for describing their excess weight. Three-hundred ninety obese adult primary care patients in the Philadelphia area were administered the Weight Preferences Questionnaire from January 2008 through February 2009. Ratings of 11 terms used to describe excess weight were transformed to a 5-point scale, ranging from "very desirable" (+2) to neutral (0) to "very undesirable" (-2). The term "fatness" (mean score -1.1 ± 1.3) was rated as significantly more undesirable than all other descriptors (P < 0.001). The terms "excess fat" (-0.6 ± 1.3), "large size" (-0.6 ± 1.3), "obesity" (-0.5 ± 1.4), and "heaviness" (-0.4 ± 1.2) were rated as significantly more undesirable then the remaining terms, which included weight problem, BMI, and excess weight (P < 0.001). In contrast, the term "weight" was viewed as the most desirable term for characterizing excess weight. Patients' preferences for terms were not significantly influenced by gender, race/ethnicity, or a BMI ≥40 kg/m(2). Practitioners who treat obesity are encouraged to avoid undesirable terms when discussing this condition with their patients. Instead practitioners may want to consider broaching the topic using more patient-friendly terms such as "weight," "BMI," "weight problem," or "excess weight."