The hunger metabolism is the emergency brake that nature has built in so that we survive as long as possible even with a low food intake. This emergency brake is already activated when we eat too little even for a few days.
In order to compensate for the lack of calories from food, muscle mass is lost first and foremost. And this is done in order to reduce energy consumption. Admittedly, fat is also nibbled on somewhat, but much less than hoped. In addition, the fat loss runs slower and slower over time, because the basal metabolic rate becomes lower and lower, and even at physical rest one consumes fewer calories than before.
The chip should help to find a healthy balance between hunger and normal metabolism.