My one son is a DDS and has had extensive study in organic chemistry, and metabolic functions of the human body. He explained that the biggest concern for diabetics, and indeed, all people, is the consumption of fructose. Simple starch is easily converted to sucrose (table sugar) by the digestive system, which is half glucose, and half fructose. The liver stores, and breaks down the fructose into triglycerides, LDL cholesterol, and becomes fatty, which can lead to impaired liver function, and sclerosis. At the same time, the pancreas detects extra sugar in the blood, and secretes ever increasing amounts of insulin to try and get cells to absorb more sugar, and remove it from the blood. But the cells already have as much sugar as required for metabolism, and so the sugar is converted to fatty tissue, which negatively affects the pancreases, and makes it more difficult for blood to flow through vessels, and capillaries, The excess blood sugar damages the kidneys, eyes, and everything else.
Consuming proteins and fats, doesn't trigger secretion of insulin, or cause the body to produce LDL cholesterol, or triglycerides. Though fats are calorie rich, they are a last resort that the body breaks down for energy when there isn't enough available sugar. It's safer to consume a fatty spare rib, than a French baguette.
As I look back over my life, I can see the progression of diabetic caused problems exactly as my son explained, and in the order he explained. I thought I was eating healthy, well balanced meals all of my life, avoiding a lot of sweets, preferring fruits, juices, and lots of root veggies, as well as whole grain breads and pasta. Foods were made from scratch, but included rich, starch laden gravies, pastry crusts, beads, crackers in my pea soup, and chili, etc. I was literally eating myself into poor health, in spite of being highly athletic, and doing all kinds of energetic activities. Add to that stress from the job, and parts of my family, and that extraordinary strength, and vitality that I maintained throughout my 40' just went away. Now, my ten year old grandson is stronger than me.
Do the research.. Learn from my mistakes. Don't make the same ones.
Seeeeya; Chief Longwind of the North