Okay, this will be quick......Actually it won't.
Think about it.
If you were to go anywhere for a service (food, repair, programming, etc.) and the job was done quickly, wouldn't you second guess the Quality or Durability of the finished product?
So why is it that we want and expect that with our bodies, our habits, and our life?
Can we make big changes in a short amount of time? Absolutely.
But the better question is, Will it last a Lifetime?
How many times have you been or heard of the person who has a new year’s resolution and by the time March rolls around, it's back to the old habits?
I've seen time and time again: a person loses a ton of weight, then slacks off, gains it back, then repeats the cycle. This is because they try to do everything at once. Too much too fast.
Old habits die hard. But with a slower and more focused approach they can perish or succumb to healthier ones.