A lesson in mealtime carb counting for type 1 diabetes

Josh is a 26-year-old accountant diagnosed with type 1 diabetes six months ago after presenting to hospital with diabetic ketoacidosis.
Josh has no other known medical conditions and his only prescribed medications are insulin glargine 22 units nocte and insulin aspart 3-5 units with meals. He lives with his partner.
Prior to his diagnosis, Josh had unintentionally lost about 7kg (9% of his body weight).
Since commencing insulin he has regained the weight he lost and stabilised with a BMI of 23.8kg/m2.