In prehistoric times humans were hunter gatherers. The process of hunting animals and gathering fruits and edible plants took a lot of energy. If we were to go back to living as people did in those times we would be lean and strong as they were.
Would you like to lose weight fast? Then just do not eat. Did you ever see those pictures of the survivors of Nazi concentration camps? They lost weight didn’t they? And they did it all with the assistance of diets enforced by their captors.
The time has come and you’ve determined that this is the time when you’re actually going to shed some weight. It’s not that you have not had this idea earlier in your life, but you are having it now and you want to make something happen. You’re thinking of just not eating for a while days. But in you’re heart you know that never works.