Inadequate nutrient intake is common in cancer patients and is associated with poor outcomes. Social factors may contribute to inadequate nutrient intake, although they have not been studied. The purpose of this study was to investigate social factors that may contribute to undereating in older adults with cancer. Participants included 30 patients, 17 women and 13 men, aged 70-99 years, who were diagnosed with pancreatic, colon, breast, lymphoma, skin, and head and neck cancers. Both participants and caregivers interpreted weight loss as a positive health outcome of cancer. Furthermore, some patients who had lost weight worked to keep the weight off by going on special diets. Patients and caregivers imbued certain foods with health-promoting qualities without corroborating scientific evidence. Cancer- and treatment-related alterations in self-identity due to changes in their bodies, in taste, and in the manner in which they must eat caused cancer patients to experience frustration and embarrassment, which led to reduced nutritional intake. Despite their compromised nutritional status, patients did not discuss food and eating habits with their physicians. Behaviors and attitudes of patients and caregivers may lead to negative changes in eating behaviors beyond the cancer itself or its treatment or sequelae. Many of these behaviors are potentially modifiable with appropriate education, communication, and intervention.