Food insecurity is associated with mental health outcomes among adults experiencing homelessness. Different mechanistic explanations have emerged to account for the inequality of health outcomes among vulnerable populations. The neomaterial theoretical perspective suggests that nutritional deficiencies from experiencing food insecurity are related to negative health outcomes. Whereas, the psychosocial theoretical perspective indicates that perceived disadvantages or inability to cope emotionally (i.e. lower distress tolerance) from food insecurity leads to adverse health outcomes. Building on the these theoretical perspectives, the purpose of the study was to examine nutrition and emotional distress tolerance as potential links between food insecurity and poor physical and mental health among adults experiencing homelessness. Adults were recruited from six area shelters in Oklahoma City (N = 566) during July–August 2016. Self-rated poor health, depression, and post-traumatic stress disorder (PTSD) were regressed on food insecurity using logistic regressions. Indirect effects of nutrition and distress tolerance were assessed using bootstrapping methods outlined by Preacher and Hayes. In covariate-adjusted models, distress tolerance, but not nutrition, partially mediated the association between food insecurity and poor health (β = 0.28, [0.14, 0.44]), depression (β = 0.56, [0.33, 0.88]), and PTSD (β = 0.39, [0.22, 0.60]). Results suggest that experiencing food insecurity may lower the ability to withstand emotional distress and consequently contributes to negative health outcomes. Accessible fruit bowls and a 24-h pantry stocked with snacks and ready-to-go meals may assist in reducing the stress associated with receiving food in shelters.