Hi,
To clarify further,
Fasting blood sugar is ideally in the range of 70 - 90
Peak post eating < 140 (ideally < 120),
Before next meal, ideally similar to fasting levels
Hi.
Yes, it can. Fat tissue increases insulin resistance, making it harder for your body to control it's blood sugar. This is particularly true for type 2 diabetes, though it can also be relevant in type 1.
This is why one of the ways to help manage diabetes is to optimize weight.
Exercise also helps reduce insulin resistance, and so may be helpful in managing blood sugars.