Since I started working from home, I found that I'm super focus and productive in the morning after consuming a cup of coffee. My productivity is at its lowest

Since I started working from home, I found that I'm super focus and productive in the morning after consuming a cup of coffee. My productivity is at its lowest after lunch, even a light one, feeling my glucose is running low. I found it helps to take a small break and do 15 min walk and come back to work re-boost my attention again. Another thing that helps is to maintain a low in-door temperature definitely adds more O2 to my brain. Maybe that's why my last workplace is always so cold with AC blasts at its max.