I am now a civvy but served 8.5yrs in the Army as a driver. 4.5yrs of that as a Type 1 Diabetic.
Diagnosed in 2000.
I eventually left in 2004 after feeling restricted by the army's mentality to a point where I felt like I had more options outside the forces.
They will not give you an MD unless you are completely useless to them or classed as disabled.
It took a good 6 months for the Medical Board to decide what I could and couldn't do.
I eventually was given a grading of P3 CPND Geo (Career non-deployable posting geographical). Basically short deployment in areas where there is established medical facilities.
It depends on what you are after our of the job-if you are happy behind a desk you will be fine but that wasn't for me.