The purpose of this study was to examine the moderating effect of couple's attachment behavior on family-of-origin (FOO) issues and body mass index (BMI). Previous research has indicated that family and couple relational factors may influence BMI. The vulnerability and stress model provided a theoretical framework for understanding how attachment behaviors may give greater adaptability to managing vulnerabilities from family stress. 1214 couples between the ages of 18 and 70, who identified themselves as in a serious relationship were surveyed using the RELATE questionnaire; both partners responded. Results indicated that there was a significant association between FOO stress and adult BMI for both males and females. There was also an association between attachment behaviors and female BMI, but not male BMI. Finally attachment behavior did not moderate the relationship between FOO stressors and BMI. Clinical implications include using clinical models that focus on intergenerational problems when weight concerns are presented in therapy and, for women especially, focusing on couple attachment behaviors when there are weight concerns.