Might diabetes be caused by eating one large meal late in the day?

Not likely . . .: Type 1 diabetes mellitus is due to pancreatic failure such that the pancreas no longer makes any insulin. That's why type 1 diabetics will forever need to take Insulin shots. Type 2 diabetes is typically due to obesity leading to Insulin resistance. In other words, the body requires more Insulin than the pancreas can produce. It's doubtful unless one large meal is composed of starchy sugary foods.