I found this recent study that looked at how bed rest affects insulin reponses. After 5 days of bed rest, subjects had a 67% higher insulin reponse to glucose than compared to normal.
On the other side of the coin, this study showed that just seven consecutive days of exercise rapidly improved insulin resistance.
It’s amazing how quickly the body can adjust to either sedentary or active behavior. All this again shows the importance of daily activity in health.