In Mexico social dynamics are changing toward less traditional arrangements. With a qualitative interview study, we explore the link between marital conflict and mothers' ability to foster healthy dietary habits. Sample consisted of 21 middle-class cohabitating mothers of preschoolers. Results suggests that marital conflict leads women to experiences of tension, ambivalence, or inaction on fostering healthy eating habits. Parents' mismatch in gender beliefs, food preferences, time orientation, and risk aversion play a role in creating disagreements. When men participate, women feel "helped" and grateful, but the forms and extent of desired participation may vary among traditional, ambivalent and non-traditional women.