Stress contributes to poor health outcomes; importantly, a stress reaction begins with the negative appraisal of a situation. The ability to use cognitive reappraisal, an emotion regulation strategy that involves reinterpreting an initial appraisal to change its emotional impact, could be a protective factor against the health consequences of stress reactivity. The present study investigated (1) if cognitive reappraisal ability acts as a stress-buffer against high body mass index (BMI) and (2) if this buffering effect persists against the indirect influences of stress reactivity on type 2 diabetes. Participants completed an online cognitive reappraisal ability (CRA) task, self-report measures of perceived stress reactivity, height, weight, and type 2 diabetes diagnosis. Results revealed that CRA significantly interacted with perceived stress reactivity to predict BMI, which indirectly predicted type 2 diabetes. Individuals who perceived elevated levels of stress reactivity yet had higher CRA, exhibited lower BMI and lower incidence of type 2 diabetes than individuals with higher perceived stress reactivity and lower CRA. Interestingly, higher CRA appeared to not be protective in those who have lower levels of perceived stress reactivity. Findings from this study suggest that emotion regulation interventions can be developed to indirectly target type 2 diabetes and similar obesity-related illnesses and must be designed according to the individual given the context-dependent nature of our results.