If you eat too much, you get high readings, too many carbs, high readings, don't eat at all, or not enough, liver thinks you're starving, dumps sugar into your system, high readings.
With high readings comes fatigue, which makes you want to sleep instead of exercise, which turns your sugar into fat, which makes you more insulin resistant which keeps your blood sugar high, which was already high because you thought if you cut back on what you ate, you could lose some weight.
If your blood sugar is too high for too long you get a whole gamut of problems. If you're a woman, bladder infections, vaginitis, loss of sex drive. A man can get ED. They can be small like acne, or big like losing toes and fingers from infection. It can cause pain in your extremities. It can give your urine a sickly sweet smell. Athletes foot, slow healing sores, frequent urination, blurred vision.
If your blood sugar is good, it's not much better. You will have sore finges from being pricked a few times a day to keep the blood testing going. You probably won't be ableto eat pizza,oatmeal, cake, carrots, potatoes in any form, candy, pancakes, BBQ sauce, ketchup. Anything that tastes good. You will fight with dieticians that will try and tell you that you need to eat 60% of your calories in carbohydrate form, even though you know if you even glance longingly at a bowl of oatmeal, your blood sugar will spike a thousand points. A piece of bread, whole grain with double protein is your treat of the day.
The worst thing is you will bore your friends and family by writing a blog entry about it.