People want to change their bodies.
They do NOT want to lose weight — despite what they may think
The body doesn't arrive at the end of the day, tot up the calories in-out then add/remove a block of fat as appropriate.
You exercise Maximum Intensity to build lean muscle and to flip the genetic switch to burnGLYCOGENonly. Then, for the rest of the 24 hours that switch goes to burnFATonly.
It is pointless to weigh yourself. Counting calories does not work, as who knows hat the day will being?
Here's the kicker — the body has no mechanism for storing protein. So, if you eat plenty of protein calories, you will gain weight but take in a caloric deficit - as muscle tissue is heavy.
Later on, you may lose/gain bodyweight as water is replenished, fat is used, etc
Also, there ARE 2 chemicals which cause adipose cells to release their contents or stick to stuff destined for fat-storage causing it to be transported out of the body.
So, basically, the objective is to gain the correct type of body tissue ... not to SIMPLY LOSE BODY TISSUE
You want plenty of proteins and healthy fats [which build the muscle cell structure], plus carbs to spare the muscles' protein during tough exertion.