IntroductionWhereas marginal food insecurity has been recognized as important in Canadian food security policy, the category of marginal food security (MFS) is often ignored in US food security research. MethodsPrevalence of FI was estimated according to the conventional and an alternate classification of MFS with food insecurity among 938 youth and young adults (YYA) with youth-onset type 1 diabetes (T1D) and 156 with youth-onset of type 2 diabetes (T2D) from the SEARCH Food Security Cohort Study (2018-2021). Multivariable regression was used to estimate the association of MFS and conventionally defined food insecurity (FI) ascertained with diabetes-related outcomes, including acute diabetes complications, health care utilization, and diabetes self-management among YYA with T1D. ResultsMFS affected 10% of participants with T1D diabetes and 20% of participants with T2D. Classifying MFS with FI increased FI prevalence from 18.0% to 27.8% in participants with T1D and 34.6% to 55.1% in participants with T2D. Compared to T1D with high food security, YYA with T1D who were FI had higher odds hypoglycemia (2.1, 95%CI 1.2-3.6) and ketoacidosis (1.6, 95%CI 1.0-2.6), but no association was seen in MFS. The FI group also had higher odds of emergency department use and hospitalization (2.3, 95%CI 1.5-3.4; 2.4, 95%CI 1.5-3.9) and lower odds of technology use and checking glucose (0.6, 95%CI 0.4-0.9; 0.3, 95%CI 0.1-0.6). The MFS group exhibited associations of similar directions. Discussion and ConclusionsHealth care providers should consider care of patients with T1D and MFS the same way they care for patients with FI.