Yikes! Aside from (what I hope is obvious) the fact that if he watched what he was eating he would have better control, he really, really, really, needs to be checking his blood sugar. Seriously.
If he's made the choice to eat whatever he wants and manage type II diabetes with insulin, the only way to effectively do that is by checking his blood sugar before and after each meal and adjusting his insulin doses... at the least, his doc can, and really should have already, given him some guidelines (meaning a chart or directions that basically say, "If your blood is this number, then take this many units of insulin").
I agree with Kevin... it sounds like he's taking too much insulin, or something else has changed.... maybe what he's eating has changed, or maybe his insulin has changed (check the prescription compared to past vials?), or maybe how he's taking his insulin has changed (does he measure it out for himself? taking it at a different time of day from before?), or even maybe his activity level has changed (more active than before?). It's possible something else medically has developed as well...
Plus, as we get older, our bodies change (Amen to that, hey?!) and we do start reacting differently to everything and anything we put in our bodies, including foods and especially medicines. He definitely needs to see his doc (someone is prescribing his insulin, right?) and maybe the doc can suggest a local diabetes educator... he does not *have* to change his diet or lifestyle, but a diabetes educator could at least help him figure out how best to use insulin...
Please give us an update and let us know how he's doing!
Changing your Insulin doses without checking your bloos sugar levels is DANGEREOUS. I am pretty sure that he is low or on the low side of normal and is taking more Insulin than he should becasue of what he thinks he is going to eat. Also, the amounts of Insulin that you take over time can change so maybe after 14 years he needs to adjust his Insulin again.