How much does family history factor into a type 2 diabetes or obesity diagnosis?

Quite a bit, for both. Having a parent or sibling with type 2 diabetes meaningfully increases your own risk, and it's one of the risk factors Diabetes Canada specifically flags as something to be aware of regardless of your own weight or lifestyle. Obesity also has a documented genetic and family component, though environment and habits still play a real role too. Family history raises baseline risk rather than being the sole determining factor. References: https://obesitycanada.ca/healthcare-professionals/adult-clinical-practice-guideline/ https://guidelines.diabetes.ca/GuideLines/media/Docs/Quick%20Reference%20Guide/2024-CPG-Quick-Reference-Guide.pdf