There are two extremes: to eat all my waking hours or to fast. I can go with the Derech Hamemutze and eat only eight hours.
The middle of the road is quite dangerous. That is where the yellow lines are. To use the Rambam’s example, one extreme is complete laziness and the other is hurried and harried and being a nervous wreck. The middle way is tempered. The middle way is actually called a ‘way’, it is measured and decision based.