**Background:** Over 460 million individuals globally have type 2 diabetes mellitus (T2DM), a condition requiring comprehensive self-management including blood glucose monitoring, medication adherence, diet, physical activity, and foot care. The COVID-19 pandemic introduced stressors and social distancing that likely disrupted these behaviors, but the extent and direction of changes were unclear. This scoping review aimed to characterize diabetes self-management behavior engagement during the pandemic and, where possible, changes from pre-pandemic levels.
**Methods:** The authors systematically searched PubMed, PsychInfo, and Google Scholar from December 2019 through August 2021 using terms including "COVID" and "diabetes" combined with lifestyle, health behavior, self-care, self-management, adherence, eating, diet, physical activity, exercise, sleep, SMBG, and CGM. Articles were restricted to English-language publications. Four calibrated reviewers extracted data following PRISMA-ScR guidelines. The search identified 1,710 articles; after screening, 24 articles were included. Articles were divided into two categories: those reporting only current health behavior frequencies during COVID-19 (n=5) and those characterizing changes from pre-COVID-19 levels (n=19).
**Key Results:** Among the 19 studies assessing change, 16 examined physical activity: 15 reported decreased physical activity or low physical activity, 3 reported no change, and 1 reported increased physical activity. Eleven studies assessed diet: results were mixed, with some reporting increased unfavorable dietary habits (decreased adherence, high fatty food/sweets consumption, increased food intake), one reporting favorable changes (increased fruits/vegetables, decreased processed foods), and four reporting no change. Eight studies examined sleep: two reported increased sleep duration, one reported decreased sleep quality, and four reported no change. Four studies assessed medication intake: two reported decreased intake and two reported no change. All five studies assessing SMBG reported no change. Six studies examined substance use: all reported no change or no alcohol/tobacco use as the modal response. Three studies examined global diabetes self-care scores: one reported no change and two reported decreased scores. Only 3 of the 19 studies used longitudinal methodology (following the same cohort over time), based in India, the United Kingdom, and Australia. Sample sizes ranged from n=56 in Japan to n=1,633 in Brazil. Most studies relied on retrospective self-report measures and cross-sectional designs.
**Clinical Implications:** The strongest evidence points to reduced physical activity during the pandemic, with no evidence of improvement in any diabetes self-management behavior at the population level. The stability of SMBG despite worsening glycemic control reported elsewhere suggests other behaviors (particularly physical activity) may be driving metabolic changes. Clinicians should prioritize problem-solving with patients to increase physical activity within pandemic constraints, consider prescribing digital health programs for diet and activity tracking, and connect patients experiencing psychological distress to mental health services. Future research should use standardized, objective measures (e.g., actigraphy for sleep/activity, uploadable glucose meters), recruit well-characterized samples, follow participants longitudinally across pandemic phases, and examine predictors of behavioral vulnerability and resilience.