The pancreas is then required to produce even higher amounts of insulin to accommodate the heightened insulin requirements. This stresses the pancreas’s beta cells to work harder and eventually poop out, but also the effects of NOT eating a diet high in veggies, beans, seeds and fruits places the pancreas at further risk from oxidative stress.
For example, twenty pounds of extra fat may force the pancreas to produce twice as much insulin to do the necessary job. Fifty pounds or more of excess fat on our frame and the pancreas may be forced to produce 6 to 10 times as much insulin as a normal person who is lean. What do you think occurs after ten or twenty years of overworking the pancreas? Again, it poops out and loses the ability to keep up with such huge insulin demands. The pancreas is still overworked, pumping out much more insulin than a thinner person might need, but still not enough to cover all that disease-causing body fat.
Adult diabetes is a disease of insulin resistance, not of insulin deficiency. The pancreas's ability to secrete insulin continues to diminish as the diabetes continues and the overweight condition continues year after year. Total destruction of insulin secreting ability almost never occurs in type-2 (adult onset) as it does in type-1 (childhood onset) diabetes. But the sooner the type-2 diabetic can lose the extra weight causing the diabetes, the more functional reserve of insulin secreting cells in the pancreas will remain.