I got rid of energy variability by just fasting through the workday and making and eating the meal after my 7,5h day. I got the drowsiness after lunch and I als

I got rid of energy variability by just fasting through the workday and making and eating the meal after my 7,5h day. I got the drowsiness after lunch and I also opted for easy to make lunches which were definitely unhealthy. By just drinking water/decaf coffee/decaf tea, and putting in an effort for a decent meal, I started getting more consistent energy levels. Your mileage may vary.