The question itself is not accurate. If weight reduction is your goal, then what you need to understand is your plan must be focused on losing fat percentage, not focusing on weight at all. It is because many factors such as losing muscle mass, bone density, changes in the bodies water level, time of the day etc. can cause significant changes in the weight. It fluctuates based on body type, climate, medical conditions etc.
It is of utmost importance that you need to make a realistic approach and choose something that you can make your lifestyle Inorder to make your results sustain for a long duration of time. Otherwise, you might be stuck inside a loop relapsing again and again ultimately giving up as every relapse will take a toll on you mentally as well.
Now out of hundreds of different dieting techniques, every single one of them carries results. But what you need to choose is the one that suits your lifestyle and which does not compromise your nutrition in any way maintaining your muscle mass, and overall health is of most importance. A realistic goal, according to the American College of sports medicine is to lose 1 pound per week. As a coach from the last 12 years of experience my most valuable advice would be there are no shortcuts in life, there is only the right way which requires you to be consistent and patient.